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Objective: The objective of this work was to develop a psychometrically sound questionnaire for measuring the on-the-job impact of chronic health problems and/or treatment ("work limitations")., Research Design: Three pilot studies (focus groups, cognitive interviews, and an alternate forms test) generated candidate items, dimensions, and response scales. Two field trials tested the psychometric performance of the questionnaire (studies 1 and 2). To test recall error, study 1 subjects were randomly assigned to 2 different questionnaire groups, a questionnaire with a 4-week reporting period completed once or a 2-week version completed twice. Responses were compared with data from concurrent work limitation diaries (the gold standard). To test construct validity, we compared questionnaire scores of patients with those of healthy job-matched control subjects. Study 2 was a cross-sectional mail survey testing scale reliability and construct validity., Subjects: The study subjects were employed individuals (18-64 years of age) from several chronic condition groups (study 1, n = 48; study 2, n = 121) and, in study 1, 17 healthy matched control subjects., Measures: Study 1 included the assigned questionnaires and weekly diaries. Study 2 included the new questionnaire, SF-36, and work productivity loss items., Results: In study 1, questionnaire responses were consistent with diary data but were most highly correlated with the most recent week. Patients had significantly higher (worse) limitation scores than control subjects. In study 2, 4 scales from a 25-item questionnaire achieved Cronbach alphas of > or = 0.90 and correlated with health status and self-reported work productivity in the hypothesized manner (P < or = 0.05)., Conclusions: With 25 items, 4 dimensions (limitations handling time, physical, mental-interpersonal, and output demands), and a 2-week reporting period, the Work Limitations Questionnaire demonstrated high reliability and validity.

A 69-item questionnaire measuring generic functioning and well-being and disease-specific health outcomes was developed and tested using the pre-treatment data from patients with chronic hepatitis C (CHC) participating in two randomized trials of interferon alpha-2b (n = 157). The questionnaire included all eight scales from the SF-36 and measures of nine other generic and disease-specific health concepts. Psychometric tests confirmed the assumptions underlying the construction and scoring of all generic and disease-specific scales. Cross-sectional tests of 'known groups' validity showed that CHC patients scored worse on the generic scales than patients with other chronic conditions and worse than a healthy general population. The generic and disease-specific scale scores were lower in the presence of physical findings of CHC, as hypothesized, but only the physical functioning and bodily pain scales were linked to cirrhosis or extreme alanine aminotransferase (ALT) ratios. This instrument will be useful in studies of health outcome among patients with CHC, a condition whose health burden appears to have been underestimated in studies to date.

The International Quality of Life Assessment (IQOLA) Project is a 4-year project to translate and adapt the widely used MOS SF-36 Health Survey Questionnaire in up to 15 countries and validate, norm, and document the new translations as required for their use in international studies of health outcomes. In addition to the eight-scale SF-36 health profile, the project will also validate psychometrically based physical and mental health summary scores, as well as health utility indexes incorporating SF-36 scales for use in cost-utility studies.