Fetal Down syndrome screening: A cost effectiveness analysis of alternative screening programs

OBJECTIVE: To compare the efficacy and cost effectiveness of different screening programs for fetal Down syndrome (DS). METHODS: Screening tools evaluated included maternal age, triple screening (TS), and ultrasound (U/S) for fetal markers of DS. Sensitivities used were TS: 55% <35 years, 80% > or = 35 years; U/S: 70%. Average regional fees used were TS: $80, U/S: $200, amniocentesis (AM): $1,000. Five screening programs were evaluated: 1) <35 years, no screening; > or = 35 years, AM; 2) <35 years, TS with AM for screen-positive subjects; > or = 35 years, AM; 3) all patients, TS with AM for screen-positive subjects; 4) <35 years, TS followed by U/S for screen-positive women, AM for women with fetal markers of DS on U/S; > or = 35 years TS with AM for screen-positive subjects; 5) all women, TS followed by U/S for screen-positive women, AM for women with fetal markers of DS on U/S. The sensitivity, total cost, cost/case DS detected (Cost/DS), AM losses, and residual risk (RR, undetected DS fetuses/women not receiving AM) were calculated for each screening program. Population analysis was performed using 1988 IL delivery statistics. RESULTS: It was estimated that 260 cases of DS would occur in the population of 167,654 women (8.4% > or = 35 years at delivery). Sensitivity for programs 1-5 was 30, 69, 62, 51, and 36 percent, respectively, and cost/DS was 181,000, 203,000, 162,000, 151,000, and 194,000 dollars, respectively. CONCLUSIONS: DS screening incorporating TS in all patients with program #4 and without program #3 selective U/S in women <35 years yield the best combination of sensitivity and cost effectiveness while minimizing the number of AM-related losses.