Next Article in Journal
Does Physical Activity Mediate the Associations Between Local-Area Descriptive Norms, Built Environment Walkability, and Glycosylated Hemoglobin?
Next Article in Special Issue
Effect of Sex and Body Mass Index on Children’s Physical Activity Intensity during Free Play at an Indoor Soft Play Center: An Exploratory Study
Previous Article in Journal
Aflatoxin B1 Contamination in Chicken Livers and Gizzards from Industrial and Small Abattoirs, Measured by ELISA Technique in Maputo, Mozambique
Previous Article in Special Issue
Predictors of Segmented School Day Physical Activity and Sedentary Time in Children from a Northwest England Low-Income Community

Int. J. Environ. Res. Public Health 2017, 14(9), 952; https://doi.org/10.3390/ijerph14090952

Article
Self-Rated Health Status and Cardiorespiratory Fitness in a Sample of Schoolchildren from Bogotá, Colombia. The FUPRECOL Study
1
Centro de Estudios para la Medición de la Actividad Física (CEMA), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá DC 111221, Colombia
2
Grupo de Ejercicio Físico y Deportes, Vicerrectoría de Investigaciones, Universidad Manuela Beltrán, Bogotá DC 110231, Colombia
3
Department of Education Sciences, University of Almería, 04120 Almería, Spain
4
PROFITH “PROmoting FITness and Health through Physical Activity” Research Group, Department of Physical Education and Sport, School of Sport Sciences, University of Granada, 18010 Granada, Spain
5
Laboratorio de Ciencias de la Actividad Física, el Deporte y la Salud, Universidad de Santiago de Chile, Facultad de Ciencias Médicas, USACH, Santiago 9160030, Chile
*
Author to whom correspondence should be addressed.
Academic Editor: Paul B. Tchounwou
Received: 25 July 2017 / Accepted: 17 August 2017 / Published: 23 August 2017

Abstract

:
To evaluate the relationship between Self-Rated Health (SRH) and cardiorespiratory fitness (CRF) in a sample of children and adolescents enrolled in official schools in Bogotá, Colombia. A cross-sectional study was performed with 7402 children and adolescents between 9 and 17 years of age. Participants were asked to rate their health based on eight validated questions, addressing the participants propensity for headache, stomach-ache, backache, feeling-low, irritability/bad mood, nervousness, sleeping-difficulties, and dizziness. The choices were “rarely or never”, “almost every month”, “almost every week”, and “more than once a week/about every day”. Participants performed the international course-navette shuttle run test to estimate CRF, and cut-off points for age and gender were used to categorize the healthy/unhealthy fitness zone according to the FITNESSGRAM® criteria. Overall, 16.4% of those surveyed reported a perception of irritability/bad mood “more than once a week/about every day”, followed by feeling-low and nervousness (both with 9.9%). Dizziness had the lowest prevalence with a percentage of 6.9%. Unhealthy CRF in boys increased the likelihood of headaches by 1.20 times, stomach aches by 1.31 times, feeling-low by 1.29 times, nervousness by 1.24 times, and dizziness by 1.29 times. In girls, unhealthy CRF increased the likelihood of headaches by 1.19 times, backache by 1.26 times, feeling-low by 1.28 times, irritability/bad mood by 1.17 times, sleeping-difficulties by 1.20 times, and dizziness by 1.27 times. SRH was associated with CRF in both genders. Early identification of children and adolescents with low CRF levels will permit interventions to promote healthy behaviors and prevent future diseases during adulthood.
Keywords:
physical activity; sedentary life style; subjective perception of health; pain; fitness

1. Introduction

Self-Rated Health (SRH) is a relevant construct for a healthy lifestyle and is used to capture a person’s perception of their overall health status [1]. Epidemiological studies and health surveys highlight perceived heath or SRH, defined as the self-assessment that the population or an individual makes of their health condition as a product of their knowledge and own interpretations without necessarily representing a clinical diagnosis by the professional health staff [2,3]. Normally, this indicator is used in population surveys and in censuses of small populations or very specific collective groups [4]. Although, this measurement is subjective, previous studies have shown a close relation between SRH and other physical and mental health outcomes [3,4].
The association between physical fitness and SRH among adolescents may differ according to sex and overall level of physical activity, i.e., the association is stronger among boys and among more physical inactive adolescents [5]. Individuals’ perceptions of their health incorporate psychological, biological, and social dimensions that are unavailable to the external observer, but also provide a dynamic assessment of their current health status while integrating their health history [5]. For example, Idler and Benyamini [6] showed in a narrative review including 27 observational studies that SRH was related to objective health and was conditioned by the recent evolution of individual skills. In populations with poor access to health services, such as school-aged children, SRH studies have been better at showing the burden of the disease than medical records [7]. In the early stages, a study of 1155 Swedish children between 6 and 13 years of age by Petersen et al. [8], found that 23% of the children self-reported weekly recurring headaches, 19% stomach aches, and 18% back pain. In Colombia, Higuita-Gutiérrez et al. [9] performed a study with 3452 adolescents and highlighted that 10% of participants reported eye diseases, 3.1% participants reported diseases of the respiratory system, and 1.1% participants reported diseases of the musculoskeletal system.
In addition, SRH has been associated with low socioeconomic level, gender (women), lower education level, use of medical services, and poor lifestyle [10,11]. Regarding lifestyle, Kujala et al. [12] stated that healthy lifestyles influence an individual’s perceived health, which is why its absence could be related to the early onset of physical symptoms and future diseases. Thus, a relationship has been described between SRH and the physical condition related to health [13], suggesting that an active lifestyle as well as good cardiorespiratory fitness probably increase self-rated health.
Physical fitness, especially the cardiorespiratory component, is considered an important health indicator in children and adolescents [14]. Previous studies by Janz et al. [15] and Castillo-Garzón et al. [16] showed that a low cardiorespiratory fitness (CRF) level during childhood was associated with a higher risk of cardiovascular and metabolic disease during adulthood. Moreover, it has been described that a lower CRF level in children and adolescents from 9 to 17 years of age is a predictive factor of physical well-being in school-aged children [17,18]; hence, including this health indicator in epidemiological surveillance systems at the educational level is clearly justified [19].
Similarly, a cross-sectional study carried out by Herman et al. [20] with Canadian school-aged children displayed that higher levels of physical activity are directly related to better SRH and a healthy nutritional status. A study by Becerra et al. [21], which included 264 adolescents from Málaga (Spain), reported an inverse relationship between peak oxygen consumption (VO2peak) and symptoms such as pain and/or fatigue (r = −0.40; p < 0.001) as well as anxiety and insomnia (r = −0.46; p < 0.001). Recently, a prospective study with over 16 years of follow up conducted by Kantomaa et al. [22] in a sample of 7063 Finnish adolescents established that a better SRH was associated with a healthier level of CRF in both sexes.
Greater knowledge of SRH in children and adolescents, as well as its relationship with physical fitness parameters, could prevent future associated health risks in this population. Hence, this study sought to evaluate the relationship between SRH and CRF in a sample of children and adolescents enrolled in official schools in Bogotá, Colombia participating in the FUPRECOL (Asociación de la fuerza prensil con manifestaciones de riesgo cardiovascular tempranas en niños y adolescentes colombianos in Spanish) study. We hypothesized that high levels of CRF are associated with rare or absent symptoms among schoolchildren.

2. Methods

2.1. Study Design and Sample Population

Schoolchildren included in this secondary analysis are part of The FUPRECOL Study carried out in Bogotá, Colombia (n = 10,000 school children). We selected 27 schools, which already had collaboration agreements established with our research center and therefore were selected primarily for pragmatic, budgetary, and logistical reasons. The FUPRECOL Study methodology has been published elsewhere [23,24]. Data were collected from 2013 to 2016 and the analysis was done in 2016. In this study, we included a sub-sample (n = 7404) of 9–17.9-year-old healthy Colombian children and adolescents (girls, n = 4124 [55.9%] and boys, n = 3280). The children and adolescents belonged to low to middle socioeconomic statuses (SES, 1–3 defined by the Colombian government), enrolled in public elementary and high schools (grades 5 through 11), and from the capital district of Bogota in a municipality in the Cundinamarca Department in the Andean region. The exclusion criteria included having a clinical diagnosis of cardiovascular disease, having Type 1 or Type 2 diabetes mellitus, being pregnant, using alcohol or drugs, and not having lived in Bogota for at least one school year. Exclusion from the study was made effective a posteriori, without the students being aware of their exclusion, to avoid any undesired situations.

2.2. Measurement of SRH

The Health Behavior in School-Aged Children (HBSC) survey is a cross-national research study conducted in collaboration with the World Health Organization Regional Office for Europe, aiming to gain new insight into, and increase the understanding of young people’s health and well-being, health behaviors, and their social context [25]. In this study, we used the SRH-HBSC [25], which addresses the SRH of several symptoms: headache, stomach ache, back ache, low emotional state, irritability or bad mood, nervousness, difficulty sleeping, and dizziness. The responses were restricted to the last six months and the frequency option was distributed into “rarely or never”, “almost every month”, “almost every week”, and “more than once a week/almost every day”. This questionnaire has adequate validity and reliability values in young populations [26]. Nevertheless, in light of the lack of psychometric properties in the Colombian population, a reliability analysis was conducted that revealed internal consistency results (Cronbach’s alpha) of 0.69. Furthermore, in a sub-sample of 229 school-aged children (mean age 12.8 ± 2.4 years, 46.2 ± 12.4 kg, 1.50 ± 0.1 m and 19.9 ± 3.1 kg/m2 in the body mass index) and a 7-day period between each test, test-retest (Kappa index) reproducibility values of 0.79 were obtained in the eight questions of the HBSC questionnaire. The surveys were applied to the school-aged children in groups of 20–50 participants in classrooms in order to maintain privacy and freedom in their fulfilment and with the presence of at least two qualified researchers. The questionnaires were completed in approximately 15 min. Prior to applying the questionnaires, the necessary guidelines were provided for their completion, highlighting the need to carefully read the items and the importance of sincerity and anonymity when answering them.

2.3. CRF Assessment

Testing procedures were consistent with guidelines for school-based fitness assessments [19]. Tests took place in the school gymnasium or on another available hard surface. CRF was measured using the 20 m shuttle run test as previously described by Léger [27]. Results were recorded to the nearest stage completed. The Léger equation was used to determine VO2peak (mL·kg·min−1) in each participant [27,28]. The reliability and validity of this test has been widely documented [27,28] and is considered a test of choice for population-based CRF assessments for schoolchildren [19]. All tests were conducted by a trained research team that provided standardized encouragement for participants during all test phases. CRF measurements in a subsample (n = 229, median age = 12.8 ± 2.4 years, 46.2 ± 12.4 kg, 1.50 ± 0.1 m, 19.9 ± 3.1 kg/m2) were recorded to ensure reproducibility on the day of the study. The reproducibility (R) of our data was R = 0.84. Intra-rater reliability was assessed by determining the intra-class correlation coefficient (ICC = 0.96, 95% CI 0.95 to 0.97) [19].

2.4. Anthropometric Variables

Body weight was measured to the nearest 0.10 kg with the participant lightly dressed using a portable electronic weight scale (Tanita® BC544, Tokyo, Japan) with a low technical error of measurement (TEM = 0.510). Body height was measured to the nearest 0.1 cm in bare or stocking feet with the adolescent standing upright against a portable stadiometer (Seca® 274, Hamburg, Germany; TEM = 0.019) [19]. Their body mass index (BMI) was calculated as their body weight in kilograms divided by the square of their height in meters.

2.5. Ethics Statement

The FUPRECOL Study was conducted in accordance with the Helsinki Declaration for Human Studies and approved by the Colombian Data Protection Authority (Resolution 008430/1993 Ministry of Health) and the Review Committee for Research on Human Subjects at the University of Rosario (Code N° CEI-ABN026-000262). All participants were informed of the study’s goals, and written informed consent was obtained from participants and their parents or legal guardians.

2.6. Data Analysis

Continuous values were expressed as means and (±) standard deviations and proportions in percentages. Differences were analyzed by Student’s t-test or Chi-square test (χ2) to explore sex differences. The differences among SRH and the categories of the CRF were tested with the χ2 test. To analyze SRH, the five response options were placed into four groups as follows: “rarely or never”, “almost every month”, “almost every week”, and “more than once a week/almost every day”. To analyze VO2peak, the CRF variable was recalculated, taking the cut-off point suggested in the 2011 FITNESSGRAM® battery [28]. Therefore, the participants were classified as having a healthy CRF if their VO2peak was 40–44 mL·kg·min−1 for boys and 38–40 mL·kg·min−1 for girls, according to their age. These age-and-sex-specific VO2peak cut-off points were validated against the presence of metabolic disorders using representative U.S. data and the 2011 FITNESSGRAM® standards [28]. Finally, a binary logistic regression adjusted by age and BMI was used to determine the association among the CRF categories and the eight questions from the SRH questionnaire. To separate the opinion of participants who saw their self-perceived health as excellent (rarely or never symptoms) from the rest, a group denoted as “sometimes symptoms” was created, combining the responses of “every week” and “more than once a week/about every day”. All analyses were adjusted by age and BMI. Analyses were performed using the Statistical Package for Social Science® software, version 24 (IBM; Chicago, IL, USA), and the level of significance was set to 0.05.

3. Results

3.1. Descriptive Characteristics

Descriptive statistics for each sex are shown in Table 1. Of the total sample (n = 10,000), 7402 school-aged children (74% rate of response) between 9 and 17.9 years of age complied with all the inclusion criteria, of which 4140 (55.9%) belonged to the group of girls. The mean age of the general population was 12.8 (2.3) years, body mass of 44.6 (12.3) kg, height 1.49 (0.12) m, and 19.7 (3.4) kg/m2 in the body mass index. The proportion of subjects with low CRF was 31.5%. An unhealthy aerobic capacity was observed in 33.9% of girls and 28.1% of boys (p < 0.001).

3.2. Self-Rated Health Status

Table 2 presents the distribution of SRH in the sample. Headache and bad mood were the most frequent psychological complaints, with different percentages among boys and girls (p < 0.05). Overall, 16.4% reported a perception of irritability/bad mood “more than once a week/about every day”, followed by feeling-low and nervousness (both at 9.9%). Dizziness had the lowest prevalence with a value of 6.9%. In terms of gender, 27.8% of the boys reported a perception of irritability/bad mood “almost every week”, followed by headache at 25.4% and stomach-ache at 20.4%. In girls, the proportion that reported irritability/bad mood “more than once a week/about every day” was at 11.6%, followed by feeling-low at 10.0%.

3.3. Relationship among SRH and CRF Categories

Table 3 shows the relationship between SRH and CRF divided in two categories (healthy and unhealthy). There were several significant differences (p < 0.05) when comparing the frequency of response between CRF categories among the four categories (“rarely or never”, “almost every month”, “almost every week”, “more than once a week/almost every day), for almost all of the eight SRH dimensions, for both girls and boys. Upon differentiating by gender, girls categorized with unhealthy CRF had a higher frequency of problems “almost every week” and “almost every month” than boys for the eight questions from the SRH questionnaire.

3.4. Factors Associated to Low CRF (Unhealthy)

Finally, Table 4 shows the binary regression model to determine the association among the low CRF and the eight questions from the SRH questionnaire. The results show that unhealthy CRF in boys, according to the 2011 FITNESGRAM® criteria, increased the likelihood of reporting headaches by 1.30 times (95% CI 1.09–1.55), stomach aches by 1.31 times (95% CI 1.09–1.58), feeling low by 1.29 times (95% CI 1.08–1.54), nervousness by 1.24 times (95% CI 1.04–1.48), and dizziness by 1.29 times (95% CI 1.05–1.59). In girls, this condition increased the likelihood of headaches by 1.19 times (95% CI 1.04–1.35), backache by 1.26 times (95% CI 1.07–1.48), feeling-low by 1.28 times (95% CI 1.12–1.46), irritability or bad mood by 1.17 times (95% CI 1.03–1.32), sleeping-difficulties by 1.20 times (95% CI 1.03–1.39), and dizziness by 1.27 times (95% CI 1.09–1.48), as shown in Table 4.

4. Discussion

The most relevant finding in this study was that boys and girls categorized with unhealthy CRF had higher odds of problems “more than once a week” and “almost every day” than healthy counterparts in the eight questions from the SRH questionnaire. As should be expected when considering such SRH, the occurrence of subjective physical complaints was relatively low in our study, with irritability/bad mood being more frequently reported, followed by headaches.
The perception of stomach-ache was higher in girls compared to boys, as previously reported [7]. Subjective indicators of health markedly differ between youth in different countries, although multiple complaints are generally declared at higher proportions in girls compared to boys. From current evidence, the relationship between physical fitness and SRH in a young population is still scarce and confusing, as well as contradictory when comparing both genders [29]. This study found significant differences in the self-reporting of sensed morbidity, finding that girls presented higher prevalence of irritability/bad mood, while boys presented higher prevalence of feeling-low. Prior studies concluded that girls tend to endure 2–3 times more self-reported health problems than boys [29]. Regarding this finding, Johnson and Richter [30] considered that SRH is an adequate indicator of real health, highlighting that girls are often more pessimistic than boys, since they tend to self-report more serious problems related to their health. This fact also coincides with the indirect estimation of CRF because girls with unhealthy CRF showed higher frequencies of somatic problems compared to boys.
A previous study has found relationships between SRH and backache, with low levels of physical activity (<6 h per week) especially in adolescent girls [31], but the physical fitness was not analyzed. In this study, the frequency of reporting experiencing this symptom “almost every day” was higher in girls (4.4% boys, 6.0% girls, p < 0.05). The importance of the study of back pain in young people is remarkable since the early appearance of this symptom is a risk factor related to pain in adulthood [32]. Another symptom in the young population that has gained importance in the scientific literature is headache [33], which is additionally associated with poor physical condition [34,35]. In our study, this factor occurs in girls and boys at frequencies of 12.1% and 6.9%, respectively. Reports show that youth with low levels of physical activity have a higher risk of suffering from frequent headaches [34]. In school-aged children, a recent study published by Vierola et al. [35] revealed that infants with low CRF were 1.95 times more prone to suffering from headaches than infants with healthy values of aerobic fitness, independent of physical activity levels. Unfortunately, we were not able to measure variables related to physical activity levels in the FUPRECOL sample. Additionally, increasing sedentary behaviors, like screen time, have been directly associated with greater presence of musculoskeletal pain and lower self-perception of health, especially in males younger than 12 years of age [36]. This finding is relevant and coincides with our results since reports indicate that these types of diseases are associated with symptoms like cephalea, which may even affect the student’s academic performance [37].
Other symptoms reported in our study were irritability/bad mood, nervousness, and feeling-low, which to our knowledge have not been studied well in this population nor have their associations with physical fitness. However, we may speculate that the presence of some of these risk factors can be associated with other unmeasured factors related to morbidity, which seem particular to this age stage, characterized by high family and school demands; nonetheless, this requires further research [38]. In this sense, Hernan-Gómez et al. [39] propose that adolescence may bring diminished positive emotions and decreased vital satisfaction with a gradual increase of negative emotions that could affect the SRH. This finding coincides with that reported by Urzúa [40], who wrote that adolescent girls have the worst perception with respect to their health, with physical well-being and particularly their perception of themselves being the two dimensions with the least favorable evaluation. This perception of themselves constitutes a warning signal for health authorities, given that it could be indicating dissatisfaction of women with their own bodies and, hence, a higher risk of the onset of inadequate nutritional habits [41]. In synthesis, the lower SRH during the school stage could certainly be related to the complexity that characterizes this stage of development, especially in girls from Bogotá, Colombia.
To date, there are few studies that have analyzed the association between SRH and fitness in a young population, including the cardiorespiratory capacity. Häkkinen et al. [42] found a direct association between SRH, physical activity and CRF in a study of 727 youths. This study shows that healthy values of CRF increased the self-perception of well-being and organic health. In keeping with this, Kantoma et al. [5] showed that SRH measured as the question: how do you consider your state of health? And the CRF, estimated using a cycle-ergometer, was associated with better scores in the SRH in Colombia, which is a result that agrees with our study. We found that an unhealthy CRF in children and adolescents is a predictive factor of physical well-being [17,18]. It is important to delve into the components of SRH to detect risk factors associated with enduring future diseases with the aim of implementing different interventions with a perspective of primary health care.
The mechanism between SRH and better CRF is not well established. One plausible explanation relates to the afferent information that conveys messages from the organism to the brain [43]. These messages are usually not brought to consciousness because they function at lower levels of the central nervous system. Another theory explaining a person’s perceptions of their health involves a family of proteins called cytokines [44]. Research is beginning to show that the subclinical inflammatory process and certain cytokines are associated with tiredness, depressive mood, pain, irritability, and poor appetite [45].
This study contained a series of limitations that must be described. The first limitation is inherent to its cross-sectional nature and type of sampling, which does not permit evaluating causality relationships. Second, it would be fitting to broaden the population object of study to different age brackets or private establishments. The reason for having selected a sample between 9 and 17 years of age is due to the variability we can find in physical activity habits during these ages. Third, the study did not evaluate levels of physical activity of the youth, factors that can modulate the results of this work. Fourth, although the evaluation of CRF in children and adolescents was carried out through a valid and standardized test in this population [19], we must bear in mind that the CRF is partially genetically determined [46]. A previous study [47] has tested the degree of agreement between various equations used to estimate VO2peak and the actual VO2peak. The equation used to estimate VO2peak in this study may have underestimated CRF by up to 12% relative to other methods and therefore may have, in isolation, inflated the prevalence of unhealthy aerobic capacity [18,48,49]. Therefore, we considered our low CRF estimates to be conservative. Furthermore, cutoffs proposed were very like the interim international criterion-referenced standards of 35 and 42 ml·kg−1·min−1 for girls and boys, respectively, to identify children and youth at risk of poor health, raising a clinical red flag [18,50]. However, there are no arguments to believe that the relationships described occur exclusively in the population from our sample, given that we observed convergence of the results with data described in other national and international studies [29,30,31,32,34], hence, the results obtained herein are not compromised.
The strengths of this research broaden the scope regarding SRH in children and adolescents because both age groups were included and the methods used did not refer to specific diseases, like diabetes and myopia, as reflected in other studies [2,10,11]. To our knowledge, this is the first study to demonstrate positive associations of CRF with SRH in Latin-American schoolchildren in a large birth cohort with objective measurements of CRF. Another strength of this study lies in the large, unselected population sample. Furthermore, it approaches specific symptoms and their frequency, which permits better guidance of the specific health needs of children and adolescents from the Latino population. Nevertheless, longitudinal studies are needed to measure other confounding factors that can interfere with the interpretation of the results, like ethnicity, socioeconomic level, physical activity levels, etc.

5. Conclusions

In summary, SRH was associated with CRF in children and adolescents of both genders. Early identification of children and adolescents with low CRF levels will permit interventions to promote healthy behaviors and prevent future diseases during adulthood.

Acknowledgments

The FUPRECOL Study was possible due to the financial support provided by the Instituto Colombiano para el Desarrollo de la Ciencia y la Tecnología “Francisco José de Caldas” COLCIENCIAS (Contract No. 671-2014 Code 122265743978). The funder had no role in the study design, data collection, data analysis and interpretation, preparation of the manuscript, or decision to publish. We would like to acknowledge data analysis support provided by Javier Martínez-Torres.

Author Contributions

Robinson Ramírez-Vélez, Carolina Silva-Moreno, Daniel H. Prieto-Benavides, Katherine Gonzalez-Ruiz and Jorge Enrique Correa-Bautista conceived and designed the study, and analysed the data; Robinson Ramírez-Vélez, Antonio García-Hermoso and Emilio Villa-González analysed the data and wrote the paper. All authors read and approved the final manuscript.

Conflicts of Interest

The authors declare no conflict of interest.

Abbreviations

The following abbreviations are used in this manuscript:
FUPRECOL project in Spanishasociación de la fuerza prensil con manifestaciones de riesgo cardiovascular tempranas en niños y adolescentes colombianos
BMIbody mass index
CRFcardiorespiratory fitness
HBSCHealth Behavior in School-aged Children
SRHSelf-rated health
VO2peakpeak oxygen consumption
TEMtechnical error of measurement

References

  1. Abellán, A. Percepción del estado de salud. Rev. Mult. Gerontol. 2003, 13, 340–342. [Google Scholar]
  2. Agudelo-Londoño, S.M.; Giraldo-Villa, A.; Romero-Nieto, V.I. Perceived health status of people from the central region of Colombia: National Health Survey, 2007. Rev. Salud Publica 2012, 14, 899–911. [Google Scholar] [PubMed]
  3. Bombak, A.E. Self-rated health and public health: A critical perspective. Front. Public Health 2013, 20, 15. [Google Scholar] [CrossRef] [PubMed]
  4. Roca, M.; Gili, M.; Garcia-Garcia, M.; Salva, J.; Vives, M.; Garcia Campayo, J.; Comas, A. Prevalence and comorbidity of common mental disorders in primary care. J. Affect. Disord. 2009, 119, 52–58. [Google Scholar] [CrossRef] [PubMed]
  5. Kantomaa, M.T.; Tammelin, T.; Ebeling, H.; Taanila, A. Emotional and behavioral problems in relation to physical activity in youth. Med. Sci. Sports Exerc. 2008, 40, 1749–1756. [Google Scholar] [CrossRef] [PubMed]
  6. Idler, E.L.; Benyamini, Y. Self-rated health and mortality: A review of twenty-seven community studies. J. Health Soc. Behav. 1997, 38, 21–37. [Google Scholar] [CrossRef] [PubMed]
  7. Boardman, J.D. Self-rated health among U.S. adolescents. J. Adolesc. Health 2006, 38, 401–408. [Google Scholar] [CrossRef] [PubMed]
  8. Petersen, S.; Bergstrom, E.; Brulin, C. High prevalence of tiredness and pain in young school children. Scand. J. Public Health 2003, 31, 367–374. [Google Scholar] [PubMed]
  9. Higuita-Gutiérrez, L.F.; Cabrera Giraldo, S.; Cardona-Arias, J. Perfil de morbilidad sentida de adolescentes escolarizados en instituciones públicas de Medellín-Colombia, 2014. Arch. Med. 2015, 11, 3–9. [Google Scholar]
  10. Asfar, T.; Ahmad, B.; Rastam, S.; Mulloli, T.P.; Ward, K.D.; Maziak, W. Self-rated health and its determinants among adults in Syria: A model from the Middle East. BMC Public Health 2007, 7, 177. [Google Scholar] [CrossRef] [PubMed]
  11. Cullati, S.; Rousseaux, E.; Gabadinho, A.; Courvoisier, D.S.; Burton-Jeangros, C. Factors of change and cumulative factors in self-rated health trajectories: A systematic review. Adv. Life Course Res. 2014, 19, 14–27. [Google Scholar] [CrossRef] [PubMed]
  12. Kujala, U.M.; Kaprio, J.; Sarna, S.; Koskenvuo, M. Relationship of leisure-time physical activity and mortality: The Finnish twin cohort. JAMA 1998, 279, 440–444. [Google Scholar] [CrossRef] [PubMed]
  13. Eriksen, L.; Curtis, T.; Grønbæk, M.; Helge, J.W.; Tolstrup, J.S. The association between physical activity, cardiorespiratory fitness and self-rated health. Prev. Med. 2013, 57, 900–902. [Google Scholar] [CrossRef] [PubMed]
  14. Garber, M.D.; Sajuria, M.; Lobelo, F. Geographical variation in health-related physical fitness and body composition among Chilean 8th graders: A nationally representative cross-sectional study. PLoS ONE 2014, 9, e108053. [Google Scholar] [CrossRef] [PubMed]
  15. Janz, K.F.; Dawson, J.D.; Mahoney, L.T. Increases in physical fitness during childhood improve cardiovascular health during adolescence: The Muscatine Study. Int. J. Sports Med. 2002, 23, S15–S21. [Google Scholar] [CrossRef] [PubMed]
  16. Castillo-Garzon, M.J.; Ruiz, J.R.; Ortega, F.B.; Gutierrez-Sainz, A. A Mediterranean diet is not enough for health: Physical fitness is an important additional contributor to health for the adults of tomorrow. World Rev. Nutr. Diet. 2007, 97, 114–138. [Google Scholar] [PubMed]
  17. Gualteros, J.A.; Torres, J.A.; Umbarila-Espinosa, L.M.; Rodríguez-Valero, F.J.; Ramírez-Vélez, R. A lower cardiorespiratory fitness is associated to an unhealthy status among children and adolescents from Bogotá, Colombia. Endocrinol. Nutr. 2015, 62, 437–446. [Google Scholar] [CrossRef] [PubMed]
  18. Ramírez-Vélez, R.; Palacios-López, A.; Humberto Prieto-Benavides, D.; Enrique Correa-Bautista, J.; Izquierdo, M.; Alonso-Martínez, A.; Lobelo, F. Normative reference values for the 20 m shuttle-run test in a population-based sample of school-aged youth in Bogota, Colombia: The FUPRECOL Study. Am. J. Hum. Biol. 2017, 29, 22902. [Google Scholar] [CrossRef] [PubMed]
  19. Ramírez-Vélez, R.; Rodrigues-Bezerra, D.; Correa-Bautista, J.E.; Izquierdo, M.; Lobelo, F. Reliability of health-related physical fitness tests among Colombian children and adolescents: The FUPRECOL Study. PLoS ONE 2015, 10, e0140875. [Google Scholar] [CrossRef] [PubMed]
  20. Herman, K.M.; Sabiston, C.M.; Tremblay, A.; Paradis, G. Self-rated health in children at risk for obesity: Associations of physical activity, sedentary behavior, and BMI. J. Phys. Act. Health 2014, 11, 543–552. [Google Scholar] [CrossRef] [PubMed]
  21. Becerra, C.; Reigal, R.; Hernández Mendo, A.; Martín Tamayo, I. Relaciones de la condición física y la composición corporal con la auto percepción de salud. Rev. Int. Cienc. Deporte 2013, 9, 305–318. [Google Scholar] [CrossRef]
  22. Kantomaa, M.T.; Tammelin, T.; Ebeling, H.; Stamatakis, E.; Taanila, A. High levels of physical activity and cardiorespiratory fitness are associated with good self-rated health in adolescents. J. Phys. Act. Health 2015, 12, 266–272. [Google Scholar] [CrossRef] [PubMed]
  23. Caicedo-Álvarez, J.C.; Correa-Bautista, J.E.; González-Jiménez, E.; Schmidt-RioValle, J.; Ramírez-Vélez, R. Waist circumference distribution in Colombian schoolchildren and adolescents: The FUPRECOL Study. Endocrinol. Nutr. 2016, 63, 265–273. [Google Scholar] [CrossRef] [PubMed]
  24. Rodríguez-Bautista, Y.P.; Correa-Bautista, J.E.; González-Jiménez, E.; Schmidt-RíoValle, J.; Ramírez-Vélez, R. Values of waist/hip ratio among children and adolescents from Bogotá, Colombia: The FUPRECOL Study. Nutr. Hosp. 2015, 32, 2054–2061. [Google Scholar] [PubMed]
  25. Booth, M.L.; Okely, A.D.; Chey, T.; Bauman, A. The reliability and validity of the physical activity questions in the WHO health behavior in schoolchildren (HBSC) survey: A population study. Br. J. Sports Med. 2001, 35, 263–267. [Google Scholar] [CrossRef] [PubMed]
  26. Roberts, C.; Freeman, J.; Samdal, O.; Schnohr, C.W.; De Looze, M.E.; Nic Gabhainn, S.; International HBSC Study Group. The Health Behavior in School-Aged Children (HBSC) study: Methodological developments and current tensions. Int. J. Public Health 2009, 54, 140–150. [Google Scholar] [CrossRef] [PubMed]
  27. Léger, L.A.; Mercier, D.; Gadoury, C.; Lambert, J. The multistage 20 metre shuttle run test for aerobic fitness. J. Sports Sci. 1988, 6, 93–101. [Google Scholar] [CrossRef] [PubMed]
  28. Lobelo, F.; Pate, R.R.; Dowda, M.; Liese, A.D.; Ruiz, J.R. Validity of cardiorespiratory fitness criterion-referenced standards for adolescents. Med. Sci. Sports Exerc. 2009, 41, 1222–1229. [Google Scholar] [CrossRef] [PubMed]
  29. Martínez-López, E.J.; Hita-Contreras, F.; Moral-García, F.E.; Grao-Cruces, A.; Ruiz, J.R.; Redecillas-Peiró, M.T.; Martínez-Amat, A. Association of low weekly physical activity and sedentary lifestyle with self-perceived health, pain, and well-being in a Spanish teenage population. Sci. Sports 2015, 30, 342–351. [Google Scholar] [CrossRef]
  30. Johnson, P.B.; Richter, L. The relationship between smoking, drinking, and adolescents’ self-perceived health and frequency of hospitalization: Anlyses from the 1997 national household survey on drug abuse. J. Adolesc. Health 2002, 30, 175–183. [Google Scholar] [CrossRef]
  31. Auvinen, J.; Tammelin, T.; Taimela, S.; Zitting, P.; Karppinen, J. Associations of physical activity and inactivity with low back pain in adolescents. Scand. J. Med. Sci. Sports 2008, 18, 188–194. [Google Scholar] [CrossRef] [PubMed]
  32. Cakmak, A.; Yücel, B.; Ozyalçin, S.; Bayraktar, B.; Ural, H.I.; Duruös, M.T.; Genç, A. The frequency and associated factors of low back pain among a younger population in Turkey. Spine 2004, 29, 1567–1572. [Google Scholar] [CrossRef] [PubMed]
  33. El-Metwally, A.; Salminen, J.; Auvinen, A.; Macfarlane, G.; Mikkelsson, M. Risk factors for development of non-specific musculoskeletal pain in preteens and early adolescents: A prospective 1-year follow-up study. BMC Musculoskelet Disord. 2007, 8, 46. [Google Scholar] [CrossRef] [PubMed]
  34. Russo, A.; Bruno, A.; Trojsi, F.; Tessitore, A.; Tedeschi, G. Lifestyle factors and migraine in childhood. Curr. Pain Headache Rep. 2016, 20, 9. [Google Scholar] [CrossRef] [PubMed]
  35. Vierola, A.; Suominen, A.L.; Lindi, V.; Viitasalo, A.; Ikävalko, T.; Lintu, N.; Väistö, J.; Kellokoski, J.; Närhi, M.; Lakka, T.A. Associations of sedentary behavior, physical activity, cardiorespiratory fitness, and body fat content with pain conditions in children: The physical activity and nutrition in children study. J. Pain 2016, 17, 845–853. [Google Scholar] [CrossRef] [PubMed]
  36. Hulsegge, G.; van Oostrom, S.H.; Picavet, H.S.; Twisk, J.W.; Postma, D.S.; Kerkhof, M.; Smit, H.A.; Wijga, A.H. Musculoskeletal complaints among 11-year-old children and associated factors: The PIAMA Birth Cohort Study. Am. J. Epidemiol. 2011, 174, 877–884. [Google Scholar] [CrossRef] [PubMed]
  37. Maples, W.C. A comparison of visual abilities, race and socioeconomic factors as predictors of academic achievement. J. Behav. Optom. 2000, 12, 60–65. [Google Scholar]
  38. Guedes, D.P.; Villagra-Astudillo, H.A.; Moya-Morales, J.M.; del Campo-Vecino, J.; Pires-Júnior, R. Health-related quality of life in Latin American adolescents. Rev. Panam. Salud Publica 2014, 35, 46–52. [Google Scholar] [PubMed]
  39. Hernan-Gómez, L.; Vásquez, C.; Hervás, G. El paisaje pmocional a loargo de la vida. In La Ciencia Del Bienestar: Fundamentos de Psicología Positiva; Vásquez, C., Hervás, G., Eds.; Alianza Editorial: Madrid, Spain, 2009; Volume 1, pp. 143–180. [Google Scholar]
  40. Urzúa, A. Calidad de vida relacionada con la salud: Elementos conceptuales. Rev. Méd. Chile 2010, 138, 358–365. [Google Scholar] [CrossRef]
  41. Flores Navarro-Pérez, C.; González-Jiménez, E.; Schmidt-RioValle, J.; Meneses-Echávez, J.F.; Correa-Bautista, J.E.; Correa-Rodríguez, M.; Ramírez-Vélez, R. Nivel y estado nutricional en niños y adolescentes de Bogotá, Colombia. Estudio FUPRECOL. Nutr. Hosp. 2016, 33, 915–922. [Google Scholar] [CrossRef] [PubMed]
  42. Häkkinen, A.; Rinne, M.; Vasankari, T.; Santtila, M.; Häkkinen, K.; Kyröläinen, H. Association of physical fitness with health-related quality of life in Finnish young men. Health Qual. Life Outcomes 2010, 8, 15. [Google Scholar] [CrossRef] [PubMed][Green Version]
  43. Gander, J.; Lee, D.C.; Sui, X.; Hébert, J.R.; Hooker, S.P.; Blair, S.N. Self-rated health status and cardiorespiratory fitness as predictors of mortality in men. Br. J. Sports Med. 2011, 45, 1095–1100. [Google Scholar] [CrossRef] [PubMed]
  44. Jylha, M. What is self-rated health and why does it predict mortality? Towards a unified conceptual model. Soc. Sci. Med. 2009, 69, 307–316. [Google Scholar] [CrossRef] [PubMed]
  45. Dantzer, R.; O’Connor, J.C.; Freund, G.G. From inflammation to sickness and depression: When the immune system subjugates the brain. Nat. Rev. Neurosci. 2008, 9, 46–56. [Google Scholar] [CrossRef] [PubMed]
  46. Bray, M.S.; Hagberg, J.M.; Pérusse, L.; Rankinen, T.; Roth, S.M.; Wolfarth, B.; Bouchard, C. The human gene map for performance and health-related fitness phenotypes: The 2006–2007 update. Med. Sci. Sports Exerc. 2009, 41, 35–73. [Google Scholar] [CrossRef] [PubMed]
  47. Boiarskaia, E.A.; Boscolo, M.S.; Zhu, W.; Mahar, M.T. Cross-validation of an equating method linking aerobic FITNESSGRAM® field tests. Am. J. Prev. Med. 2011, 41, S124–S130. [Google Scholar] [CrossRef] [PubMed]
  48. Sandercock, G.; Voss, C.; Cohen, D.; Taylor, M.; Stasinopoulos, D.M. Centile curves and normative values for the twenty metre shuttle-run test in English schoolchildren. J. Sports Sci. 2012, 30, 679–687. [Google Scholar] [CrossRef] [PubMed]
  49. Ramos-Sepúlveda, J.A.; Ramírez-Vélez, R.; Correa-Bautista, J.E.; Izquierdo, M.; García-Hermoso, A. Physical fitness and anthropometric normative values among Colombian-Indian schoolchildren. BMC Public Health 2016, 16, 962. [Google Scholar] [CrossRef] [PubMed]
  50. Lang, J.J.; Tremblay, M.S.; Ortega, F.B.; Ruiz, J.R.; Tomkinson, G.R. Review of criterion-referenced standards for cardiorespiratory fitness: What percentage of 1 142,026 international children and youth are apparently healthy? Br. J. Sports Med. 2017. [Google Scholar] [CrossRef] [PubMed]
Table 1. Characteristics of among a population-sample of Schoolchildren in Bogota, Colombia.
Table 1. Characteristics of among a population-sample of Schoolchildren in Bogota, Colombia.
 Characteristics Girls Boys Overall
 (n = 4140) (n = 3280) (n = 7402)
 Age (years) 12.8 (2.4) 13.1 (2.4) * 12.8 (2.3)
 Body mass (kg) 44.9 (11.4) 45.3 (13.2) ** 44.6 (12.3)
 Height (m) 1.47 (0.10) 1.56 (0.14) * 1.49 (0.12)
 BMI (kg/m2) 20.9 (3.5) 19.7 (3.3) * 19.7 (3.4)
 VO2peak (mL·kg−1·min−1) a 38.7 (4.8) 42.9 (5.2) * 40.2 (5.3)
 Shuttles (total count) 21.3 (11.3) 36.6 (20.0)* 28.9 (17.9)
 Stage (last completed) 2.7 (1.3) 4.4 (2.2) * 3.6 (2.1)
 Running speed at last completed shuttle (km·h1) 9.0 (1.8) 9.9 (2.1) * 3.7 (2.2)
 FITNESSGRAM® (VO2peak fitness zones) n, [%] b
 Needs improvement 1062 (25.6) 551 (16.7) * 1613 (21.8)
 Low CRF (unhealthy) 1407 (33.9) 924 (28.1) * 2331 (31.5)
Note: Frequencies in brackets represent the proportion of the total sample with data for each variable; Significant between-sex differences (t student or Chi-square; * p < 0.001; ** p < 0.01); a VO2peak (mL·kg−1·min−1) predicted using the Leger et al. equation [27]; b To classify VO2peak, we used the 2011 FITNESSGRAM® standards and healthy fitness zones [28].
Table 2. Frequency of self-rated health status in a sample of schoolchildren from Bogotá, Colombia. The FUPRECOL Study.
Table 2. Frequency of self-rated health status in a sample of schoolchildren from Bogotá, Colombia. The FUPRECOL Study.
QuestionFrequencyOverall (n = 7402)Girls (n = 4140)Boys (n = 3280)p Value
HeadacheRarely or never4703 (63.3)2989 (72.2)1714 (52.3)<0.001
Almost every month600 (8.1)302 (7.3)298 (9.1)0.367
Almost every week1392 (18.8)559 (13.5)833 (25.4)<0.001
More than once a week/almost every day725 (9.8)290 (7.0)435 (13.3)0.010
Stomach acheRarely or never4837 (65.1)2935 (70.9)1902 (58.0)<0.001
Almost every month903 (12.2)480 (11.6)423 (12.9)0.638
Almost every week1177 (15.9)509 (12.3)668 (20.4)<0.001
More than once a week/almost every day503 (6.8)215 (5.2)288 (8.8)0.125
BackacheRarely or never5525 (74.4)3175 (76.7)2350 (71.6)<0.001
Almost every month718 (9.7)406 (9.8)312 (9.5)0.026
Almost every week785 (10.6)377 (9.1)408 (12.4)0.188
More than once a week/almost every day392 (5.3)182 (4.4)210 (6.4)0.444
Feeling-lowRarely or never4548 (61.2)2347 (58.7)2201 (67.1)<0.001
Almost every month933 (12.6)497 (12.0)436 (13.3)0.644
Almost every week1199 (16.2)799 (19.3)400 (12.2)<0.001
More than once a week/almost every day740 (9.9)497 (10.0)243 (7.4)0.249
Irritability/bad moodRarely or never3475 (46.7)2227 (53.8)1248 (38.0)<0.001
Almost every month955 (12.9)567 (13.7)388 (11.8)0.353
Almost every week1776 (24)865 (20.9)911 (27.8)<0.001
More than once a week/almost every day1214 (16.4)480 (11.6)734 (22.4)<0.001
NervousnessRarely or never4733 (63.7)2757 (66.6)1976 (60.2)<0.001
Almost every month807 (10.9)489 (11.8)318 (9.7)0.359
Almost every week1140 (15.4)555 (13.4)585 (17.8)0.059
More than once a week/almost every day740 (9.9)339 (8.2)401 (12.2)0.071
Sleeping-difficultiesRarely or never5155 (69.4)2894 (69.9)2261 (68.9)0.442
Almost every month740 (10)431 (10.4)309 (9.4)0.648
Almost every week903 (12.2)530 (12.8)373 (11.4)0.663
More than once a week/almost every day622 (8.4)286 (6.9)336 (10.2)<0.001
DizzinessRarely or never5428 (73.2)3200 (77.3)2228 (67.9)<0.001
Almost every month696 (9.4)389 (9.4)307 (9.4)0.989
Almost every week777 (10.5)348 (8.4)429 (13.1)0.035
More than once a week/almost every day511 (6.9)195 (4.9)316 (9.6)0.055
Table 3. Relationship between self-rated health status and cardiorespiratory fitness in a sample of schoolchildren from Bogotá, Colombia. The FUPRECOL Study.
Table 3. Relationship between self-rated health status and cardiorespiratory fitness in a sample of schoolchildren from Bogotá, Colombia. The FUPRECOL Study.
QuestionOverall (n = 7420)Girls (n = 4140)Boys (n = 3280)
Healthy (n = 4558)Unhealthy a (n = 2844)p ValueHealthy (n = 2381)Unhealthy a (n =1759)p ValueHealthy (n = 2177)Unhealthy a (n = 1103)p Value
Headachen (%)n (%) n (%)n (%) n (%)n (%)
 Rarely or never3010 (64.1)1683 (35.9)<0.0011388 (59.8)933 (40.2)0.0151622 (68.4)750 (31.6)<0.001
 Almost every month343 (57.3)256 (42.7)199 (55.6)159 (44.4)144 (59.8)97 (40.2)
 Almost every week798 (57.5)590 (42.5)510 (53.9)436 (46.1)288 (65.2)154 (34.8)
 More than once a week/almost every day407 (56.4)315 (43.6)284 (57.1)213 (42.9)123 (54.7)102 (45.3)
Stomach ache
 Rarely or never3051 (63.3)1770 (36.7)<0.0011474 (59.0)1023 (41.0)0.2231577 (67.9)747 (32.1)0.001
 Almost every month538 (59.5)366 (40.5)290 (55.4)233 (44.6)248 (65.1)133 (34.9)
 Almost every week688 (58.6)486 (41.4)428 (55.6)342 (44.4)260 (64.4)144 (35.6)
 More than once a week/almost every day281 (55.9)222 (44.1)189 (56.9)143 (43.1)92 (53.8)79 (46.2)
Backache
 Rarely or never3468 (63.0)2041 (37.0)<0.0011773 (59.2)1220 (40.8)0.0061695 (67.4)821 (32.6)0.049
 Almost every month420 (58.7)296 (41.3)217 (55.2)176 (44.8)203 (62.8)120 (37.2)
 Almost every week447 (56.8)340 (43.2)251 (51.2)239 (48.8)196 (66.0)101 (34.0)
 More than once a week/almost every day223 (57.2)167 (42.8)140 (56.9)106 (43.1)83 (57.6)61 (42.4)
Feeling-low
 Rarely or never2889 (63.7)1649 (36.3)<0.0011405 (60.0)935 (40.0)0.0021484 (67.5)714 (32.5)0.023
 Almost every month581 (62.3)352 (37.7)286 (57.7)210 (42.3)295 (67.5)142 (32.5)
 Almost every week675 (56.4)522 (43.6)420 (52.8)376 (47.2)255 (63.6)146 (36.4)
 More than once a week/almost every day413 (56.3)321 (43.7)270 (55.1)220 (44.9)143 (58.6)101 (41.4)
Irritability/bad mood
 Rarely or never2183 (63.1)1274 (36.9)0.0111010 (59.7)681 (40.3)0.0561173 (66.4)593 (33.6)0.356
 Almost every month600 (63.0)352 (37.0)295 (58.9)206 (41.1)305 (67.6)146 (32.4)
 Almost every week1058 (59.6)718 (40.4)596 (54.6)496 (45.4)462 (67.5)222 (32.5)
 More than once a week/almost every day717 (58.9)500 (41.1)480 (57.3)358 (42.7)237 (62.5)142 (37.5)
Nervousness
 Rarely or never2944 (62.4)1774 (37.6)0.0171468 (58.0)1064 (42.0)0.9141476 (67.5)710 (32.5)0.004
 Almost every month503 (62.3)304 (37.7)244 (58.1)176 (41.9)259 (66.9)128 (33.1)
 Almost every week697 (61.0)445 (39.0)407 (57.8)297 (42.2)290 (66.2)148 (33.8)
 More than once a week/almost every day414 (56.3)321 (43.7)262 (56.2)204 (43.8)152 (56.5)117 (43.5)
Sleeping-difficulties
 Rarely or never3216 (62.6)1923 (37.4)0.0301682 (59.1)1163 (40.9)0.0511534 (66.9)760 (33.1)0.287
 Almost every month452 (61.2)287 (38.8)222 (55.6)177 (44.4)230 (67.6)110 (32.4)
 Almost every week533 (58.9)372 (41.1)258 (53.1)228 (46.9)275 (65.6)144 (34.4)
 More than once a week/almost every day357 (57.7)262 (42.3)219 (55.9)173 (44.1)138 (60.8)89 (39.2)
Dizziness
 Rarely or never3428 (63.3)1991 (36.7)<0.0011716 (59.5)1169 (40.5)0.0071712 (67.6)822 (32.4)0.006
 Almost every month412 (58.9)287 (41.1)215 (55.1)175 (44.9)197 (63.8)112 (36.2)
 Almost every week443 (57.2)332 (42.8)262 (52.7)235 (47.3)181 (65.1)97 (34.9)
 More than once a week/almost every day275 (54.0)234 (46.0)188 (53.7)162 (46.3)87 (54.7)72 (45.3)
a To classify CRF, we used the 2011 FITNESSGRAM® standards and healthy fitness zones (healthy and unhealthy) [28].
Table 4. OR and 95% CI for “sometimes symptoms (more than once a week/almost every day)” of self-perceived health according to low cardiorespiratory fitness (unhealthy) in a sample of schoolchildren from Bogotá, Colombia. The FUPRECOL Study.
Table 4. OR and 95% CI for “sometimes symptoms (more than once a week/almost every day)” of self-perceived health according to low cardiorespiratory fitness (unhealthy) in a sample of schoolchildren from Bogotá, Colombia. The FUPRECOL Study.
QuestionBoysGirls
OR95% CIOR95% CI
Headache
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day1.301.09–1.551.191.04–1.35
Stomach ache
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day1.311.09–1.581.100.96–1.27
Backache
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day0.950.87–1.441.261.07–1.48
Feeling-low
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day1.291.08–1.541.281.12–1.46
Irritability/bad mood
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day1.040.89–1.221.171.03–1.32
Nervousness
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day1.241.04–1.481.030.90–1.19
Sleeping-difficulties
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day1.140.96–1.371.201.03–1.39
Dizziness
 Rarely (almost every month) or neverReferenceReference
 More than once a week/almost every day1.291.05–1.591.271.09–1.48
Note: OR: odds ratio; CI: confidence interval. Self-perceived health (“sometimes symptoms” was created, combining the responses of “every week” and “more than once a week/about every day) were included in the logistic regression as a variable category; ORs were adjusted for age and BMI (body mass index).

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Back to TopTop