[Changes in clinical condition and causes of death of inpatients with Duchenne muscular dystrophy in Japan from 1999 to 2012].

To elucidate changes in medical treatment for Duchenne muscular dystrophy (DMD) in Japan, we analyzed the clinical courses and causes of death of inpatients with DMD registered in the muscular dystrophy ward database of 27 hospitals in Japan specializing in muscular dystrophy treatment since 1999. The total number of hospitalized cases in 1999 was 873, which gradually reduced to 733 in 2012. The mean age of DMD patients in 1999 was 23.6 years old, while that was 30.1 years old in 2012, with patients 40 years and older accounting for 94 cases in the latest year. The respirator dependent rate gradually increased from 58.6% in 1999 to 86.1% in 2012. Artificial respiration therapy was introduced earlier in more recent years and the mean age in recent years was shown to be 17.2 years old. The oral nutritional supply rate in 1999 was 95.1%, which fell to 66.8% in 2012, while gastrostomy feeding gradually increased to 129 cases in 2012. The rate of clinical diagnosis of DMD was 52.3% in 1999 and decreased to 43.7% in 2012, which showed progress towards more accurate diagnosis of DMD. From 2000 to 2012, 521 deaths were reported, with approximately half of the causes heart related, followed by respiratory related. The mean age of death gradually increased to 32.4 years old in 2012 from 26.7 years old in 2000. The mean age of survival of all DMD patients was 37.5 years old. Progress in multidisciplinary medical care for respiratory failure, cardiomyopathy, nutritional problems, and other related factors has extended the lifespan of DMD patients.