Quality of life, physical disability, and respiratory impairment in Duchenne muscular dystrophy

Rationale: Duchenne muscular dystrophy (DMD) leads to progressive, generalized paresis, and to respiratory failure in the second decade of life. The assumption that severe physical disability precludes an acceptable quality of life is common, but has not been specifically evaluated in DMD. Objectives: The purpose of this study was to investigate the quality of life in relation to physical disability, pulmonary function, and the need for assisted ventilation in DMD. Methods: In 35 patients with DMD, aged 8-33 yr, we assessed physical disability by a score ranging from 9 (no disability) to 80 (complete dependence on care and technical aids), pulmonary function, and health-related quality of life by Short-Form 36 of the medical outcome questionnaire. Measurements and Main Results: All patients required a wheelchair and help for dressing and eating. Fourteen patients were on long-term noninvasive positive-pressure ventilation. In ventilated patients, mean +/- SD FVC was 12 +/- 10 % predicted, and the physical disability score was 65 +/- 7. Corresponding values in spontaneously breathing patients were 48 +/- 25 % predicted, and 51 +/- 7, respectively (p < 0.05 for both comparisons between groups). Short-Form 36 physical function scores were massively reduced in both groups (1 +/- 2, and 0 +/- 0, respectively), but vitality, role-emotional, social function, and mental health scores were nearly normal (67-98), and did not differ between groups. Conclusions: Quality of life in DMD is not correlated with physical impairment nor the need for noninvasive positive-pressure ventilation. The surprisingly high quality of life experienced by these severely disabled patients should be taken into consideration when therapeutic decisions are made.