A study of long-term survival, functional outcome and quality of life in patients with polymyositis or dermatomyositis

Abstract

There have been few studies of long-term functional outcomes and quality of life in patients with polymyositis or dermatomyositis.

Patients: 28 patients, 16 female and 12 male, meeting Bohan's and Peter's criteria and admitted between 1970 and 1993, were studied retrospectively; nine had polymyositis and 19 dermatomyositis (with onset during childhood in five cases); mean age was 43.5 years.

Methods: we reevaluated 18 of the 28 patients, after a mean interval of eight years; among the ten remaining patients, eight had died, one could not be traced and one declined reevaluation. Survival, muscle function, joint function, respiratory function and quality of life (AIMS 1) were determined. Factors predicting the value of these parameters were looked for.

Results: significant excess mortality was observed as compared with the general population in the Seine Maritime region of France. Easy fatigability and decreased exercise tolerance were found in 50% of evaluated patients; Ritchie's index was 0 in 67% of patients and between 1 and 7 in 33%; 55% of patients had dyspnea and 50% had abnormal respiratory function parameters; quality of life items were usually rated "fairly good" or "very good", except for "physical activities", which were given "poor" or "very poor" ratings by one third of patients. We found no factors associated with survival or any of the above-mentioned functional parameters, except for male gender, which predicted better muscle function.

Discussion: polydermatomyositis is associated with excess mortality; alterations in muscle function persist in half the cases and the ability to carry out physical activities is often reduced. The retrospective design of our study, small sample size and heterogeneity of our population precluded identification of factors predictive of survival, loss of function, or poor quality of life.