2. Materials and Methods
2.1. Definition of Terms
2.2. Search Methods
2.3. Inclusion Criteria
2.4. Exclusion Criteria
2.5. Selection Process
2.6. Evaluation of Psychometric Properties; Statistical Analysis, Reliability and Validity
2.7. Evaluation of Items
3.1. Evaluation of Psychometric Properties; Statistical Analysis, Reliability and Validity
3.2. Evaluation of Items
Conflicts of Interest
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|Measure||Test||Definition of Test||Noble et al. (2019)||Tatlock et al. (2017)||Freeman et al. (2016)||Bijsmans et al. (2016)||Lavan (2013)||Yeates et al. (2011)||Villalobos (2011)||Mullan et al. (2007)||Wojciechowska et al. (2005)|
|Statistical analysis to determine tool structure||Factor analysis (FA) or principal component analysis (PCA)||FA identifies correlations between and among variables (i.e., items) to organise them into underlying factors (i.e., domains). PCA estimates proportions of variance within a set of variables (i.e., items) to transform large amounts of data into smaller sets.||✓||✓||✓||✓||✓|
|Reliability||Internal consistency||Determines how well items within the tool measure the same construct. Assessed using statistical measures (e.g., Cronbach’s alpha) to determine whether correlations exist between items grouped together within a domain.||✓||✓||✓||✓||✓|
|Test–retest reliability||Indicates whether the tool yields consistent results when administered to the same person on two separate occasions.||✓||✓||✓||✓||✓||✓|
|Inter-rater reliability||Agreement among responses when the tool is administered by two or more scorers.|
|Validity||Content validity||The extent to which the tool measures the construct it is designed to measure. Can be established if the target population (i.e., pet owners) or panel of experts (i.e., veterinarians) contribute to item generation and cognitive interviewing.||✓||✓||✓||✓||✓||✓||✓||✓||✓|
|Criterion validity||Determines whether responses to items agree with a ‘gold standard’ (i.e., an external criterion known to measure the same concept).|
|Construct validity||The extent to which items or domains measure what they are meant to be measuring. Assessed by determining whether relationships among items or domains conform to existing hypotheses or theories (i.e., known-group validity, convergent validity).||✓||✓||✓||✓||✓||✓|
|Publication||Species||Function of Tool||Development of Tool||Testing of Draft Tool||Description of Final Tool|
|Noble et al. 2019||Cats||Generic QoL tool for cats||Semi-structured interviews with owners of healthy and sick cats to generate 165 items. An online survey was completed by cat owners and vets to screen for relevance and clarity. Draft questionnaire consisted of 39 items.||Field test one: 71 cat owners (n = 41 sick, n = 30 healthy) completed the draft questionnaire online.|
Field test two: 94 cat owners (n = 58 sick, n = 36 healthy) completed the revised questionnaire online. In total, 48 of these owners completed the questionnaire a second time two weeks later.
|Three domains (vitality, comfort and emotional well-being) with 20 items. Items answered using 7-point Likert scales.|
A final question ‘Is your cat perfectly healthy?’ was included, but was not assessed in the study.
An algorithm was used to generate three domain scores to determine a cat’s QoL (algorithm not described by authors).
|Tatlock et al. 2017||Cats||Tool for evaluating QoL in cats for use in general veterinary practice||Cat owners (n = 45) conducted an online survey followed by cognitive debriefing interviews (n = 10) to generate a draft QoL containing 22 items.||A sample of 199 owners of healthy cats completed the draft questionnaire online twice, two weeks apart.||Two domains (healthy behaviours and clinical signs) with 16 items. Items answered using 5-point Likert scales.|
An algorithm was used to generate QoL scores; 0 (lowest QoL) to 100 (highest QoL).
|Freeman et al. 2016||Cats||Generic QoL tool for cats||Focus groups of cat owners (n = 23) developed 155 items, followed by cognitive debriefing interviews with novel cat owners (n = 31). |
Draft tool (Cat Health and Well-Being (CHEW) questionnaire) consisted of 100 items.
|Sample of 1303 owners of healthy cats completed draft CHEW online; 391 of these owners completed it a second time 7 days later.||CHEW. Eight domains (mobility, emotion, energy, engagement, eyes, coat, appetite and fitness) with 33 items in total. Items answered using 6-point Likert scales plus N/A option.|
Contained two broad questions regarding 1) owner’s perception of a cat’s overall QoL and 2) a cat’s overall health.
Computer-generated QoL score ranged between 0 (lowest QoL) to 100 (highest QoL).
|Bijsmans et al. 2016||Cats||Generic QoL tool for cats. Also used to compare healthy cats to those with chronic kidney disease (CKD)||Focus group of vets (n = 5), vet nurses (n = 2) and cat owners (n = 32) developed 18 items included in draft tool (CatQoL).||Sample of 204 cat owners completed CatQoL online. Compared three groups of cats; old healthy (n = 35), young healthy (n = 94) and chronic kidney disease (CKD) (n = 70).||CatQoL. Four domains (general health, eating, behaviour and management) with 16 items. Items answered using 4-point or 7-point Likert scales.|
Contained one broad question regarding general QoL (1 = very poor; 10 = excellent).
Computer-generated average-weighted impact score (AWIS) provided QoL measure.
|Lavan 2013||Dogs||Generic QoL tool for dogs, developed for use in clinical and research settings||Owners of healthy dogs (n = 60) reviewed a cancer treatment survey developed by the author to determine appropriate items. Draft canine health-related QoL survey (CHQLS-21) consisted of 21 items.||Sample of 174 owners of healthy dogs completed the draft CHQLS-21 online; 86 of these owners completed it a second time 2 weeks later.||CHQLS-15. Four domains (happiness, physical functioning, hygiene and mental status) with 15 items. Items answered using 5-point Likert scales.|
Contained two open ended questions on general health and an item asking for a direct QoL assessment (1 = very poor; 10 = excellent).
Computer-generated QoL score for each domain was determined by the sum of item scores.
|Yeates et al. 2011||Dogs||Tool was designed to encourage discussions and decisions about dogs’ QoL||An expert panel of dog owners, vets and welfare scientists (n = 7) generated the QoL tool.||Two randomised controlled trials in which 170 owners were either given the tool during a consult (tool group, n = 91) or not (control group, n = 79). Dog owners were questioned after the consult regarding QoL discussions and decisions.||Seven items (food, exercise, comfort, company of humans, company of other dogs, routine veterinary care and care of illnesses) answered via visual analogue scales.|
No QoL score generated.
|Villalobos 2011||Dogs and cats||Provides a guideline for caregivers of terminally ill pets to assess QoL and assist in end of life decisions||Author developed HHHHHMM QoL scale.||None||Seven domains (hurt, hunger, hydration, hygiene, happiness, mobility and more good days than bad). Variable number of items per domain Each domain answered using a 10-point Likert scale.|
A score of >35 deemed acceptable QoL.
|Mullan and Main 2007||Dogs||Generic QoL tool to raise awareness regarding the welfare of pet dogs visiting a veterinary clinic||Expert focus group of vets, animal welfare specialists and behaviourists (n = 15) revised/refined a QoL questionnaire developed by the author.||Sample of 27 dog owners completed the questionnaire twice on two consecutive days.||Four part questionnaire containing 39 items.|
Part 1: personality and history.
Part 2: 16-point Likert scale questions regarding comfort, exercise, diet, mental stimulation and companionship.
Part 3 and 4: 22 visual analogue scale questions regarding behaviour.
A concluding question required owners to list three important changes they would make to improve their dog’s QoL.
No single QoL score generated.
|Wojciechowska et al. 2005||Dogs||Discriminative questionnaire for assessment of non-physical aspects of QoL of pet dogs||Items were generated by the authors using personal veterinary experience and literature regarding animal welfare, veterinary medicine and canine behaviour. A focus group of five dog owners were also consulted. A panel of nine experts reviewed the draft questionnaire which consisted of 38 items.||A total of 120 dog owners (n = 43 healthy dogs, n = 77 sick dogs) completed the questionnaire via telephone interview.|
Owners of healthy dogs (n = 43) were reinterviewed three to four weeks later.
|Five domains (satisfaction of telos needs, opportunities for pleasure, minimal fear and distress, distressing events and being outdoors) consisting of 27 items.|
Response options were assigned the letter grades O, A, B and C, (O = best QoL; C = worst QoL). These grades were designated the values 4 (O), 3 (A), 2 (B), and 1 (C) on an interval scale. QOL score = (mean grade/4) X 100%. The maximum possible score was 100%, whereas the minimum possible score was 25%.
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