To assess health related quality of life (HRQOL) and functional ability across groups of chronic diseases in Spain.
A national health survey was conducted during 1999-2000. Participants were randomly selected from city censuses among persons aged over 20 years. All 2192 participants (response rate 73%) completed generic instruments measuring functional ability in activities of daily living [Health Assessment Questionnaire (HAQ)] and HRQOL [Short-Form 12 (SF-12)]. Chronic diseases were defined by self-report and elicited from 2 specific questions: "Have you ever been told you have a chronic disease by a physician?" and "Are you taking any chronic medication?". Only diagnoses present for > or = 3 months were included as chronic. We estimated mean HAQ and SF-12 scores for the different groups of chronic diseases. We then adjusted the scores for covariates and compared them between diseases by multiple linear regressions.
Over half the population had at least one chronic disease [n = 1276 (58.2%)], and 22.6% had any rheumatic disease. Rheumatic diseases have an adverse effect on daily functioning [HAQ beta-coefficient 0.11 (95% CI 0.06-0.15)] and HRQOL [SF-12 physical beta-coefficient -5.78 (95% CI -6.27 to -4.28); SF-12 mental beta-coefficient -2.61 (95% CI -3.79 to -1.41)]. Thus, the influence of the rheumatic diseases is greater when their prevalence is taken into account.
When the definition of burden of disease includes a measure of function and HRQOL that is weighted by disease prevalence, rheumatic diseases as a group can be ranked alongside neurological, cardiac, or pulmonary conditions as a major disease.