Elsevier

Neuromuscular Disorders

Volume 12, Issue 10, December 2002, Pages 926-929
Neuromuscular Disorders

Survival in Duchenne muscular dystrophy: improvements in life expectancy since 1967 and the impact of home nocturnal ventilation

https://doi.org/10.1016/S0960-8966(02)00140-2Get rights and content

Abstract

We reviewed the notes of 197 patients with Duchenne muscular dystrophy whose treatment was managed at the Newcastle muscle centre from 1967 to 2002, to determine whether survival has improved over the decades and whether the impact of nocturnal ventilation altered the pattern of survival. Patients were grouped according to the decade of death and whether or not they were ventilated. Kaplan Meier survival analyses showed significant decade on decade improvement in survival. Mean age of death in the 1960s was 14.4 years, whereas for those ventilated since 1990 it was 25.3 years. Cardiomyopathy significantly shortened life expectancy from 19 years to a mean age of 16.9 years.

Better coordinated care probably improved the chances of survival to 25 years from 0% in the 1960s to 4% in the 1970s and 12% in the 1980s, but the impact of nocturnal ventilation has further improved this chance to 53% for those ventilated since 1990.

Introduction

Duchenne muscular dystrophy (DMD) is an X-linked muscular dystrophy affecting one in 3500 male live births. It causes relentlessly progressive skeletal muscle wasting and, without treatment, patients rarely survive beyond their teens as the condition also causes progressive respiratory muscle weakness and respiratory failure [1]. Cardiomyopathy is responsible for the earlier death of around 10% of boys although significant cardiac changes are inevitable with increasing age [2].

Currently no treatment is available to prevent or arrest the progressive muscle weakness. Nocturnal ventilation is a treatment for respiratory failure in DMD that is not routinely offered to all patients and despite reports from USA [3] and more recently from UK [4] there still remain ethical uncertainties around the long-term benefits of this treatment for patients with advanced DMD. This may be because of perceived lack of quality of life, as well as the paucity of direct evidence of increased survival. Only four studies of neuromuscular patients on nocturnal ventilation were included in a recent Cochrane report [5], and the only randomised trial of nasal intermittent positive pressure ventilation in DMD (which used it prophylactically rather than for symptomatic patients) reported worse survival in the treated group [6].

Patients in the Northern Region of England began to be managed at a dedicated multidisciplinary clinic in the early 1970s. We have been offering ventilation to patients at the Newcastle muscle centre since 1989 although the first patients did not accept home ventilation until 1991. Since then our policy has evolved such that by the middle of the 1990s, all patients with respiratory failure were offered nocturnal ventilatory assistance.

We undertook this retrospective study to determine:

  • (a)

    if survival has improved in DMD over the last decades, and

  • (b)

    whether the introduction of nocturnal ventilation had altered the pattern of survival.

This has not previously been formally demonstrated in DMD, although survival data over time are available for other fatal conditions such as cystic fibrosis [7].

Section snippets

Patient group

We reviewed the notes of all patients diagnosed with DMD who were managed at the Newcastle muscle centre from 1967 to 2002 The Northern region of England has a particularly stable population that facilitates lifetime management within the same centre. We excluded seven patients who walked over the age of 13 since this is suggestive of an intermediate or Becker muscular dystrophy, and seven patients with incomplete notes who did not have routine follow-up at this centre. We documented age and

Results

There were no significant differences in the mean age that walking independently became impossible between the groups. The mean age walking stopped for the whole population was 9.3 years. However, the survival curves in Fig. 1 illustrates decade-wise improvement in survival from the 1960s to date with significant differences between survival curves using the log rank test in each decade (see Fig. 1). We then compared survival since 1990 between the ventilated and non-ventilated populations (

Discussion

This is a retrospective study over a period of evolving practise, and as such has limitations. Nonetheless, the increase in life expectancy has been so striking in our ventilated group that we believe it is worth reporting. We began to offer nocturnal ventilation in the early 1990s with no systematic bias in the recruitment of patients to treatment. This is borne out by the fact that by all applicable measures, the groups of patients who did or did not accept ventilation were comparable. For

Acknowledgements

The Newcastle Muscle Centre receives financial support from the Muscular Dystrophy Campaign.

References (9)

There are more references available in the full text version of this article.

Cited by (0)

View full text