Routine antenatal anti-D prophylaxis for RhD-negative women: a systematic review and economic evaluation.

OBJECTIVES: To identify any evidence for advances in the use of routine antenatal anti-D prophylaxis (RAADP) since the 2002 National Institute for Health and Clinical Excellence (NICE) appraisal, and to assess the current clinical effectiveness and cost-effectiveness of RAADP for Rhesus D (RhD)-negative women. DATA SOURCES: Main bibliographic databases were searched from inception to July 2007. REVIEW
METHODS: Selected studies were assessed and data extracted using a standard template and quality assessment based on published criteria. Meta-analysis was used where appropriate, otherwise outcomes were tabulated and discussed within a descriptive synthesis. The health economic model developed for the 2002 NICE appraisal of RAADP was modified to assess the cost-effectiveness of different regimens of RAADP.
RESULTS: The clinical effectiveness searches identified 670 potentially relevant articles. Of these, 12 papers were included in the review, relating to eight studies of clinical effectiveness. With one exception, no additional studies were identified in comparison with the previous assessment report, and some of the studies of clinical effectiveness included in the 2002 review had to be excluded because they did not use currently licensed doses. Therefore, eight studies comparing RAADP with no prophylaxis were identified in the clinical effectiveness review and nine (including the 2001 assessment report itself) in the cost-effectiveness review. The clinical efficacy studies were generally of poor quality and did not provide a basis for differentiating between regimens of RAADP. The best indication of the likely efficacy of a programme of RAADP comes from two non-randomised community-based studies. The pooled results of these suggest that such a programme may reduce the sensitisation rate from 0.95% (95% CI 0.18-1.71) to 0.35% (95% CI 0.29-0.40). This gives an odds ratio for the risk of sensitisation of 0.37 (95% CI 0.21-0.65) and an absolute reduction in risk of sensitisation in RhD-negative mothers at risk (i.e. carrying a RhD-positive child) of 0.6%. The identified studies suggest that RAADP has minimal adverse effects. Of the nine studies in the cost-effectiveness review, only two described a model that could be applicable to the NHS. The economic model modified from the 2002 appraisal suggests that the cost per quality-adjusted life-year (QALY) gained of RAADP given to RhD-negative primigravidae versus no treatment is between 9000 pounds and 15,000 pounds, and for RAADP given to all RhD-negative women rather than to RhD-negative primigravidae only is between 20,000 pounds and 35,000 pounds depending upon the regimen. The sensitivity analysis suggests that the results are reasonably robust to changes in the assumptions within the model.
CONCLUSIONS: RAADP reduces the incidence of sensitisation and hence of haemolytic disease of the newborn. The economic model suggests that RAADP given to all RhD-negative pregnant women is likely to be cost-effective at a threshold of around 30,000 pounds per QALY gained. The total cost of providing RAADP to RhD-negative primigravidae in England and Wales is estimated to be around 1.8-3.1 million pounds per year, depending upon regimen, and to all RhD-negative pregnant women in England and Wales around 2-3.5 million pounds.