Current Knowledge, Attitudes, and Practice among Health Care Providers in OSCC Awareness: Systematic Review and Meta-Analysis

OSCC remain a global health problem. Lack of awareness leads to inadequate watchfulness regarding early signs/symptoms despite the ease of visual oral inspection. What clinicians know and feel, and how they behave on OSCC is crucial to understand the feasibility and effectiveness of screening programs. The aim of this systematic review was to assess knowledge, attitudes, and practice (KAP) regarding OSCC among health care providers (HCPs). Therefore, a systematic review was conducted with SPIDER and PICO as major tools. A meta-analysis was structured through common items in two comparison groups of medical and dental practitioners. Descriptive statistics and a Mantel–Haenszel test were used to validate data. Sixty-six studies were selected for systematic review, eight of which are useful for meta-analysis. A statistically significant difference was recorded between dentists and medical practitioners for questions regarding: Alcohol (p < 0.001); Elderly (p < 0.012); Sun exposure (p < 0.0001); Erythroplakia (p < 0.019); Red patch (p < 0.010); White patch (p < 0.020); Tobacco consultation (p < 0.0001); Intraoral examination (p < 0.0001) and Up-to-date knowledge (p < 0.002). Overall, the incidence of OSCC screening is low. Most HCPs feel the need to increase KAP. Data confirmed gaps in KAP, highlighting the need for a more efficient pre- and post-graduation training, necessary to increase competence worldwide.


Introduction
Oral cancer is a large global health problem where statistical data have changed little over time, with 177,757 deaths out of 377,713 new cases recorded in 2020 and with a low 5-year survival rate of 50% [1,2]. The oral cavity is easily accessible for routine screening through clinical examination; therefore, in theory, dysplastic changes should be straightforwardly detected and diagnosed in the early stages, leading to more effective management. Oral squamous cell carcinoma (OSCC) is the most common type of oral neoplasms, accounting for over 90% of oral cancers. Visual screening for OSCC is quick (requiring only five minutes), simple, inexpensive, and non-invasive, and it causes little discomfort to the patients, whereas the detection of most solid malignancies in their early asymptomatic stages usually requires special, costly, and often invasive techniques [3]. However, most of the oral lesions are detected in their late stage, often too late for any therapeutic treatment [4].
The WHO has listed early screening and prevention as the priority objectives to keep under control OSCC global spread: Early detection, including opportunistic screening of asymptomatic populations and awareness of early signs and symptoms, increases the probability of cure [5]. In this context, health care providers (HCPs) such as dentists, maxillofacial surgeons, general physicians, otolaryngologists (ENTs), and dermatologists play a crucial role [6][7][8] since they are well trained to provide oral examination and to screen the presence of suspicious lesions. This good practice might help not only in primary prevention but also in timely OSCC detection.
The perception of knowledge, attitudes, and practices (KAP) among HCPs in this field is mainly explored and studied through research projects based on surveys, either face-toface interviews or questionnaires [9]. The knowledge possessed by a medical community refers to its OSCC understanding; attitude refers to its feelings towards the disease, as well as to any preconceived ideas that it may have towards it; practice refers to the ways in which it demonstrates its knowledge and attitude through actions [10]. Understanding the levels of KAP would allow pre-and post-graduate training programs to be modified according to the needs of the medical community, focusing on the fields where there is a greater need for training [11,12].
In our field of interest, the understanding of KAP among HCPs is a key step to minimize OSCC risk, improve prevention and control measures, and apply detection procedures, because oropharyngeal cancers can be recognized at an early stage by visual and tactile examination. On the other hand, the assessment of KAP is also essential because it has a key role in counseling patients regarding OSCC early detection [13].
In this systematic review, all studies measuring OSCC-KAP among dentists and physicians were collected with the purpose to summarize and compare knowledge, feelings, and behaviors among medical (MDs) and dental practitioners (DDSs).

Materials and Methods
The systematic review relied on a PRISMA statement with the use of Sample, Phenomenon of Interest, Design, Evaluation, and Research Type (SPIDER) and Population, Intervention, Comparison, Outcome (PICO) tools in order to structure the research question [14][15][16]: "Is there any difference in KAP among HCPs regarding OSCC?".

Eligibility Criteria
The review included qualitative, quantitative, and mixed-method studies written in the English language. Studies investigating the current knowledge status and/or skills and/or attitudes and/or perceptions and/or practices and/or behaviors of MDs and DDSs were taken into account.

Search Strategy
The used databases were PubMed and Scopus. The search strategy was based both on medical subject headings (MeSH) and on the following key words, in multiple combinations, which were chosen to reflect the focus of the review: "Oral cancer", "oral neoplasm", "oral malignant", "knowledge", "awareness", "early detection", "prevention". Studies published up to December 2020 (included), from any year, were sought. In addition, the search was supplemented by searching of the reference lists of the included studies.

Study Selection
Two authors were involved in the literature search. The choice of the reference studies was made firstly on the screening of titles and abstracts of all the articles after the exclusion of duplicates, in an unblinded but independent process. The independent lists were cross-referenced; any disagreement was resolved by consensus or with a third-party reviewer. Then, in line with inclusion and exclusion criteria (Table 1), a full-text eligibility assessment was performed by the two reviewers in a blinded process, after which the process of referencing and citation searching was made. A 100% agreement rate was obtained between the two authors.

Data Extraction and Data Synthesis
A standardized form was used to extract data from the included studies. To assess the aim of the review, the following data were collected: Author's name, year of publication, purpose of study, sample size, type of HCP's, and OSCC-related items explored in the questionnaire-based surveys classified in three distinct domains, including knowledge, attitude, practice, and outcomes related to these domains. In particular, the knowledgerelated items consisted of eleven statements about risk factors, seven about non-risk factors, six regarding oral potentially malignant disorders (OPMDs), six related to common sites of development, and eleven about clinical presentation. Seventeen statements investigated attitude items. To regard practice items, four statements were associated with physical examination and biopsy, seven with history taking, and one referral to a specialist. A detailed explanation of the explored items in the questionnaires and surveys is reported in Table 2.

Quality Assessment
The methodological quality of the studies was assessed according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) scale.
Where possible, a meta-analysis was structured through common items in two comparison groups of HCPs.

Statistical Analysis
The assessed items were the following ones: Alcohol, Elderly, Sun exposure, Erythroplakia, Red patch, White patch, Tobacco counseling, Intraoral examination, and Up-to-date knowledge. Overall, for the systematic review purpose, descriptive statistics of selected items among HCPs were obtained, reporting absolute numbers and percentages. In order to evaluate differences in knowledge and perception of each OSCC acknowledged risk factor between DDSs and MDs, meta-analysis was conducted by the Mantel-Haenszel method (random effects model). The possibility of heterogeneity across the studies was assessed with an I 2 test. The data analysis was performed using a commercially available statistical software (IBM SPSS, IBM Corporation, Armonk, NY, USA) with a p-value < 0.05 considered statistically significant.

Discussion
KAP studies and their related methodologies are one of the best ways to assess health care delivery by identifying gaps in knowledge and facilitating educational processes, with the important advantage of collecting a large amount of qualitative and quantitative data that will be subjected to statistical analysis. While "Knowledge" had more objective items to assess, "Attitude" was difficult to analyze because it was strictly related to acquired characteristics of an individual, including cognitive, affective feeling elements, and a tendency to action [82]. The quality of included studies was varied and heterogeneous and there were dissimilarities in design, samples, and results; data examination from two focus group uncovered several similar themes.
This systematic review revealed that knowledge among DDSs about tobacco and alcohol was satisfactory and highlighted their consolidated role in the etiology of the disease. In addition, among MDs the knowledge on tobacco, alcohol and prior oral cancer was sufficient [66,[68][69][70][71][72][73][74][75][76]79,80]. Otherwise, regarding HPV and diet in the DDS group, inadequate level of knowledge was demonstrated by the very small number of articles where they were considered and by the low scores assigned by participants. Furthermore, betel quid chewing and sun exposure, even if recognized by many DDSs, were taken into consideration in a small number of articles, 21% and 36%, respectively. Even in the MD group, the level of knowledge about HPV, elderly, diet, and betel quid chewing was low [66,70,72,77]. Few studies evaluated the "controversial risk factors" [19,35,37,40,46,55,61,75,76] (poor oral hygiene and decay teeth), in line with the current scientific literature, not yet supported by sufficient scientific evidence and therefore not yet a stable part of the clinical diagnostic OSCC management. Regarding knowledge of OPMDs, some particularly surprising data also emerged: Only 50% of the studies among DDSs assessed knowledge of OPMDs [12,[18][19][20]22,23,27,30,[37][38][39][40][43][44][45][46]48,49,51,55,57,58,60,65,74,75,78,79]; this is a very low value compared to the evidence in the literature. OPMDs was considered as a risk factor by a single article out of the 58 analyzed and recognized as such by 60.9% of DDSs [74]. The data analysis also revealed a significant lack of knowledge regarding oral sub-mucous fibrosis (OSMF) [74], since it was evaluated in one single study; this fact disagrees with the current knowledge which recognizes it as a well-known OPMD [83]. These data are clearly in contrast with current knowledge; in fact, prevention and early detection of such conditions have the potential not only of decreasing the incidence but also of improving the survival of people who develop OSCC [84]. Instead, the majority of studies (75%) among MDs investigated knowledge on OPMDs showing a higher knowledge to recognize leukoplakia [67][68][69]71,72,74,75].
A good level of knowledge among DDSs has also emerged with regard to the common high-risk sites of cancer development such as tongue and floor of the mouth [85]. On the other hand, from the 6 studies analyzing the same item among MDs, a poor expertise to recognize the floor of the mouth as a high-risk area emerged [76]. OSCC knowledge is indispensable for the correct execution of screening program, a pivotal step in early detection. It involves an oral examination with the objective of identifying changes, which may precede or predict, with a high likelihood, the development of the disease [86].
Regarding attitude, reported in 72% and 56% of study among DDSs and MDs respectively, both HCPs identified the same items.
Regarding practice items, a significant gap in knowledge with respect to the diagnostic procedures emerged. DDSs, often despite being aware of the OSCC clinical characteristics, did not perform or were unable to perform proper clinical patients' management (physical examination, history taking, risk factor examination, and referral). In particular, as part of the physical examination, it was found that DDSs rarely resort to biopsy during their activity, which is crucial in detection. Biopsy technique is an easy-to-learn competence skill, but it is the practical and last result of a previous comprehensive and complex knowledge acquisition in this field; it is important to know how to perform biopsy, but, first of all, why/where/when to perform biopsy. Research shows that few DDSs would perform a biopsy on their patients. However, waiting times for patients to be seen at specialist centers may be long. The diagnostic delay for the patient may have a negative impact on survival and cure rates [87]. Only seven studies among DDSs and two studies among MDs analyzed the habit of referring patients to specialists and there was a higher trend among DDSs than MDs [29,33,40,41,48,50,67,81].
Moreover, data analysis showed that most MDs are interested in history taking [69,72,73,77,78]. To date, the history taking in dentistry field is often an underestimated and neglected aspect. Probably this is due to the fact that during the degree course the efforts are mostly focused on the practical aspects, with consequent loss of the medical background which should be crucial for the clinical algorithm acquisition. Perhaps in Italy after the division of the two-degree programs of "Medicine and Surgery" and "Dentistry and Dental Prostheses", dental profession has been considered as a separate section of medicine, this way losing the basic knowledge of medicine that should be shared with medical profession. In fact, both professions operate in complete synergy, where systemic diseases can show different signs in the oral cavity and, at the same time, the mouth can be the first site of the onset of systemic diseases. First of all, DDSs are "physicians" of the mouth and nearby structures, also specialized in oral care and they can first detect pathological changes of Head/Neck soft and hard tissues. They must become aware of themselves and of their primary role in patient's health. In particular, in the academic programs it would be necessary to join the first three-year period of study between dental and medical students, in order to create a common pathway of knowledge and learning. As for the other focus group, also in this case physicians know they play an important role in the OSCC early diagnosis, but they feel they are not updated and lack adequate knowledge.
It was possible to compare KAP of DDSs and MDs for 8 studies used for the metaanalysis. Although the two groups agreed on most of the items, significant differences of opinions were found in 9 out of the 20 items considered (p < 0.05 from the Mantel-Haenszel test). In particular, DDSs are better trained to identify the following risk factors-Alcohol (p < 0.001), Elderly (p < 0.012) and Sun exposure (p = 0.0001)-to perform the intraoral examination (p < 0.0001), and to recognize the white/red lesions (p < 0.020; p < 0.010). Instead, MDs are more able to provide tobacco cessation counseling than DDSs. This is due to the fact that smoking is associated with a range of diseases, causing a high level of morbidity and mortality and it is a major preventable cause of death. Quitting smoking has important health benefits and the physicians are in a unique position to help patients quit tobacco [88].
The diversity in methodology and quality of included studies may have compromised the reliability of findings. In fact, the main difficulty encountered has been to standardize data for analysis. The absence of a standardized questionnaire for the evaluation of KAP on OSCC was a barrier for data comparison.
This review identified gaps among HCPs towards OSCC primary and secondary prevention, with a very disappointing scenario. HCPs showed mixed attitudes with inconsistent clinical practices related to routine OSCC screening, patient counseling, and referrals. The referral pattern lacked details, justifying global data on the diagnostic OSCC delay [89]. These findings suggest the need for further education and training on timely diagnosis and referral in association with patient guidance to promote OSCC awareness.
Patients' responsibility in diagnosis delay is only one side of the problem. It is also necessary to analyze the HCPs' commitment to the OSCC prevention and diagnosis [90].
HCPs play a pivotal role in this setting and it is imperative to improve their knowledge. Actions to be taken could be many and in different areas: (i) Education and awareness campaigns on traditional and emerging risk factors; (ii) implementation of knowledge in undergraduate training for a better understanding of causative factors and pathogenesis; (iii) annually free and mandatory education programs post-graduation. In order to reach as many HCPs as possible, continuing education programs should be a combination of different approaches and media (oral presentation, journals, poster).
As for education, in some studies it emerged that not only the postgraduate training system is insufficient to guarantee adequate preparation, but it is also needed to improve degree programs involving more activities by trainees and greater frequency to oral medicine units, as well as to participate in mandatory national/regional annual thematic meetings [91].
In addition, targeted policies and strategies should be promoted by competent organizations, such as the NHS and National Dental Associations, in order to make people aware of the possibility that nobody is immune to mouth cancer.

Conclusions
It is mandatory to improve knowledge, attitudes, and practice among DDSs and MDs about OSCC through the actions described above. Only in this way can we hope for a trend inversion, which will lead to an early diagnosis increase, to an improvement in the patient's survival rate and to a reduction of the negative economic impact on public health systems, in particular due to a large number of cases presented in late stages (III/IV) for the treatment of cancer.

Data Availability Statement:
The data that support the findings of this study are available from the corresponding author upon reasonable request.

Conflicts of Interest:
The authors declare no conflict of interest.