Prevention of Reoccurrence of Duchenne Muscular Dystrophy in Affected Families : Costeffective Analysis of Carrier Detection in Relatives of the Patients

บทคัดย่อ

         Duchenne muscular dystrophy (DMD) is a genetic disorder affecting males, characterized by progressive muscle weakness, gradual loss of ambulation, and death by 16-20 years. Female who carries mutation of this gene in only one allele is usually asymptomatic, or so called “carrier”. Carrier detection is important approach to prevent reoccurrence in the affected families. To demonstrate cost-effectiveness analysis of carrier detection among female relatives of the patients for prevention of reoccurrence, analyses on cost-effectiveness, incremental cost-effectiveness ratio, cost saving, and cost per case prevention were conducted . Clinical data of DMD families followed-up at Ramathibodi Hospital during 2000-2007 were retrospectively reviewed. Family interviews and prospective estimations of medical and non-medical expenses were conducted. The number of preventable cases was adjusted according to possible declining of pregnancy, prenatal diagnosis, and termination of pregnancy. Cost-effectiveness and related economic measurements were analyzed.

      Cost of preventing a new reoccurring DMD case was compared to the total life time cost of a DMD patient. A total of 7 DMD families which had familial reoccurrence and complete data for analysis were enrolled in the study. There were 16 reoccurring cases and 127 carrier-at-risk females. The number of expected preventable cases was 13.55. In order to prevent a reoccurring DMD case, the incremental cost was 44,309 baht and cost saving for the family and society was 1,394,386 baht.

       Sensitivity analysis showed that the lowest level of cost saving for the family and society was 1,077,914 baht. By using an approach of carrier detection among female relatives-at-risk to prevent a reoccurring case, an average of 9.37 females needed to be tested for each family, and investment of 1 baht could result into saving of 31.47 baht, indicating ample cost effectiveness. In addition, there was significant intangible cost that could not be measured by this study, such as suffering of the patients and their families for more than a decade before ending up with death of the patients. Governmental policy should be set up to support appropriate referral system and collaborative preventive program for devastating genetic disorders including Duchenne muscular dystrophy.

Key words: cost-effectiveness, incremental cost-effectiveness ratio, cost per case prevention, cost-benefit analysis, cost saving, Duchenne muscular dystrophy, X-linked recessive disorder, prevention of genetic disorder, carrier detection