Content of quality-of-life instruments is affected by item-generation methods.

BACKGROUND: Methods used to generate items for complex measurement scales are heterogeneous and probably produce heterogeneous data, yet nothing is known about the advantages of one method over another. OBJECTIVE: We aimed to compare methods of generating items for tools designed to measure quality-of-life for patients. METHODS: We used five methods to develop a quality-of-life instrument for patients with lower-limb osteoarthritis: individual interviews with patients involving two different techniques (semi-structured and cognitive), individual interviews with health professionals, and focus groups of patients and health professionals. The process generated 80 items, of which 37 were excluded after content and psychometric analysis. With the final 43-item scale used as a 'reference standard', we estimated the contribution of each method. RESULTS: For health professionals, the focus group and individual interviews produced 35 and 81% of the items, respectively. For patients, the focus groups produced 74% of the items and both interview techniques 100% of the items. Health professionals provided a narrower picture of the effects of the disease on quality-of-life. Focus groups contributed less to social domains than did individual interviews. The two patient interview techniques highlighted different themes. CONCLUSION: In developing a complex measurement scale for patients, we found individual interviews with patients the best method for formulating items; other methods such as physician interviews and focus groups contributed no additional information. Reports of instrument generation should include details of the item-generation step, the methods used to develop items and the number of people involved.

Development and testing of a specific quality-of-life questionnaire for knee and hip osteoarthritis: OAKHQOL (OsteoArthritis of Knee Hip Quality Of Life).

OBJECTIVE: To design a quality-of-life (QOL) instrument specific for patients with knee or hip osteoarthritis and to assess its validity and reproducibility. METHODS: One-on-one or group interviews were conducted with 79 patients and 28 healthcare professionals. Of the 80 potential items identified from the results, 46 were selected based on their content and were used to develop version 1 of the OsteoArthritis of Knee and Hip Quality of Life Scale (OAKHQOL). The psychometric characteristics of the scale were evaluated in patients who met Altman's criteria for knee or hip osteoarthritis. RESULTS: Based on the results of psychometric analyses in 263 patients, three items were excluded, leaving 43 items in the final version (2.3) of the OAKHQOL. Principal components analysis identified four domains: physical activities, mental health, social functioning, and social support. A pain domain was individualized later. Construct validity, reproducibility, and discriminating power of the domains were satisfactory. Standardized response means after joint replacement surgery were close to 1 for the pain and physical functioning domains and equal to 0.7 for the mental health domain, indicating good sensitivity to change. CONCLUSIONS: The OAKHQOL is the first QOL tool specifically dedicated to lower-limb osteoarthritis. It captures specific aspects of QOL in patients with knee or hip osteoarthritis and exhibits psychometric properties consistent with use in longitudinal studies.

OAKHQOL: a new instrument to measure quality of life in knee and hip osteoarthritis.

OBJECTIVE: To develop a questionnaire with which to measure quality of life (QoL) in patients with knee and hip osteoarthritis (OA). STUDY DESIGN AND SETTING: Thirty-two caregivers and 96 OA patients were interviewed individually (using cognitive and face-to-face techniques) and in focus groups. A group of experts working independently at first and then consensually used the interview transcripts to generate a 46-item questionnaire. RESULTS: Analysis of questionnaires completed by 263 patients with hip or knee OA resulted in the exclusion of three items (two because of low reliability and one because of a low response rate). Principal component analysis revealed four factors: physical activity, mental health, social functioning, and social support. A pain dimension was individualized. Preliminary testing showed the reliability of the five dimensions to be satisfactory (intraclass correlation coefficients: 0.70-0.85), construct validity was adequate when correlated with the SF36 (Spearman correlation coefficients: 0.43-0.75), and discrimination was satisfactory. The osteoarthritis knee and hip quality of life questionnaire (OAKHQOL) consists of 43 items in five dimensions and three independent items. CONCLUSION: The OAKHQOL is the first specific knee and hip OA quality of life instrument. Its development followed an a priori structured strategy to ensure content validity. It meets psychometric requirements for validity and reliability.

Quality of life in rural and urban populations in Lebanon using SF-36 health survey.

BACKGROUND: Measuring health status in a population is important for the evaluation of interventions and the prediction of health and social care needs. Quality of life (QoL) studies are an essential complement to medical evaluation but most of the tools available in this area are in English. In order to evaluated QoL in rural and urban areas in Lebanon, the short form 36 health survey (SF-36) was adapted into Arabic. METHODS: SF-36 was administered in a cross-sectional study, to collect sociodemographic and environmental variables as well as self reported morbidity. We analysed a representative sample containing 1632 subjects, from whom we randomly picked 524 subjects aged 14 years and over. The translation, cultural adaptation and validation of the SF-36 followed the International Quality of Life Assessment methodology. Multivariate analysis (generalized linear model) was performed to test the effect of habitat (rural on urban areas) on all domains of the SF-36. RESULTS: The rate of missing data is very low (0.23% of items). Item level validation supported the assumptions underlying Likert scoring. SF-36 scale scores showed wide variability and acceptable internal consistency (Cronbach's alpha >0.70), factor analysis yielded patterns of factor correlation comparable to that found in the U.S.A and France. Patients resident in rural areas had higher vitality scores than those in urban areas. Older people reported more satisfaction with some domains of life than younger people, except for physical functioning. The QoL of women is poorer than men; certain symptoms and morbidity independently influence the domains of SF-36 in this population. CONCLUSION: The results support the validity of the SF-36 Arabic version. Habitat has a minor influence on QoL, women had a poor QoL, and health problems had differential impact on QoL.