Cost-benefit analysis of thalassemia screening in Thai adolescence

Duantida Songdej¹, Ampaiwan Chuansumrit¹, Nongnuch Sirachainan¹, Oraluck Pattanaprateep², Praguywan Kadegasem¹, Pakawan Wongwerawattanakoon¹, Werasak Sasanakul^1

1Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand, ²Sector for Epidemiology and Medical Statistics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand

Backgrounds: Although a Thai national policy to antenatally screen couples at risk of having affected babies with severe thalassemia has been implemented for decades, at least 12,000 patients were born each year. An important reason for these preventable events is late first antenatal clinic visit. Therefore, thalassemia screening starting from early child-bearing age is required.

Objectives: To identify the most cost-benefit thalassemia screening package for Thai adolescence.

Methods: A total of 97 secondary school students in Ayutthaya province were explored for thalassemia using Mean Corpuscular Volume (MCV), 2,6-Dichlorophenol-Indophenol Precipitation (DCIP), Hemoglobin (Hb) electrophoresis and DNA analysis for 7 common deletional and 2 non-deletional α-thalassemia. Combination of all test results were used as a gold standard for diagnosis of thalassemia. Three potential packages for thalassemia screening were proposed; (1) MCV and DCIP, (2) MCV and Hb electrophoresis, (3) MCV, Hb electrophoresis and DNA analysis for the South East Asian (SEA) deletion. Data from the study group were used as a base to compare relevant costs for each thalassemia screening package and no screening strategy. Cost-benefit analysis was performed using decision tree model, calculated according to health burdens over the patients’ lifetime. Tornado sensitivity analysis was conducted to investigate the effect of parameter uncertainty.

Results: Mean (SD) age of enrolled students were 13 (±0.6) years and 51.5% of the students were female. Twenty-two students (23%) are carriers at risk of having a child with severe thalassemia, including Hb Bart’s hydrops fetalis, β-thalassemia major and β-thalassemia/Hb E. The screening using MCV and DCIP showed sensitivity and specificity to detect carriers at risk of 95% and 83% respectively, whereas the screening using MCV and Hb electrophoresis provided a higher sensitivity of 100% and similar specificity of 83%. Surprisingly, detection of the SEA deletion did not show additional benefits. MCV and Hb electrophoresis were also shown to be the most cost-benefit among the three potential screening packages. These two tests cost 360 Baht (US $ 11) per subject, whereas the cost for taking care of one severe thalassemia patient comprises 2.3 million Baht (US $ 67,647). Based on this study model, a difference of incremental benefit to incremental cost of thalassemia screening using MCV and Hb electrophoresis, as compared to no screening strategy, is 22,153 Baht (US $ 652) per capita of general Thai adolescence.

Conclusion: Mean corpuscular volume and hemoglobin electrophoresis are the most cost-benefit thalassemia screening in Thai adolescence.