Screening for thalassemia: an economics viewpoint.

Thalassemia presents individual, social and economic burdens: a key question is whether medical and economic viewpoints converge or not. Using precise molecular probes, prenatal diagnosis of the various thalassemia genotypes is available in the case of parents who are known carriers, so identified because of a previous affected child or a positive family genetic history. However, the ideal option of prevention of the birth of a first affected child requires community screening. The only practical approach thereto is prenatal screening of women in early pregnancy at ante-natal clinics (ANC). The initial steps (OF, DCIP) are simple, cheap and easily coupled with standard prenatal procedures. In the second phase, spouse screening, compliance is suboptimal and involves non-routine opportunity costs. Subsequent steps (secondary screening of positive pairs, genotyping of positives, and fetal diagnosis [PND]) represent greater costs to provider and consumer, and, as they are relatively expensive, reduced compliance at each step if the major part of the economic burden (direct and indirect costs) is to be borne by the consumer. Thus, only a proportion of cases is likely to face the final decision to terminate pregnancy or not. Some broad estimates of costs of each phase (ANC-->PND) have been made for comparison with the estimated costs of case management of the several thalassemia disease classes for their projected lifetimes, while several more detailed studies are in progress to fine tune the real costs (direct and indirect) of diagnosis. In a purely economic sense the situation presents opportunity to consider trade-offs between PND and disease case management, in terms of benefit:cost ratio. Viewed from a health systems vantage point this ratio depends substantially on compliance, as the system must consider the cost of caring for all thalassemia cases, including those births which could have been avoided by optimal compliance. In ideal circumstances the rough estimates indicate a probable benefit:cost ratio > 1, supporting the notion of community-based screening. Such a result, however, compares procedures in a short, finite time frame (diagnosis) with a less predictable, longer life-time (case management), requiring bureaucratic flexibility (if the public provider is to pay) or family emotional/fiscal investment (if the consumer is to pay) or both (cost-sharing): either way there is an inescapable element of long term investment planning that requires squaring off of the emotional, social and fiscal ingredients in the equation. In this sense the thalassemia syndromes represent an example of decision-making pathways involved in assessing and handling chronic disease burdens at family, community and national levels: at the latter level regional incidence varies considerably, a geopolitical factor which may require differential demographic planning.