Objective: To study the feasibility, reliability, and validity, of a Spanish European version of the Health Assessment Questionnaire (SHAQ).
Methods: A total of 170 patients with rheumatoid arthritis (RA) from 11 public general hospitals in Spain were included. We studied (a) the feasibility of the SHAQ by finding the proportion of patients able to self-administer it and the time they take to do so; (b) the test-retest reliability of the SHAQ when completed twice, with an interval of one week, calculating the Pearson correlation coefficient (r) between the first and second SHAQ scores; (c) the criterion validity of the SHAQ by comparing the clinician's assessment of the patient's activities (observed disability) with the scores noted by the patient in the questionnaire (referred disability); (d) cross sectional construct validity comparing the scores of the SHAQ with the other tests used in the assessment of RA; and (e) the longitudinal construct validity of the SHAQ comparing the difference between the initial and final SHAQ scores with the patient rating of improvement or worsening after a 3-month followup.
Results: The SHAQ was self-administered by 63% of patients, the rest needed the presence of an interviewer. The time taken to complete the questionnaire was 6.4 min. Test-retest reliability (r = 0.89), criterion validity (r = 0.87), cross sectional construct validity, and longitudinal construct validity were satisfactory and similar to other HAQ versions used in different countries.
Conclusion: The SHAQ is a reliable, valid tool, but for use in Spain an interviewer may be necessary.