Screening for postnatal depression in primary care: cost effectiveness analysis

Objective To evaluate the cost effectiveness of routine screening for postnatal depression in primary care. Design Cost effectiveness analysis with a decision model of alternative methods of screening for depression, including standardised postnatal depression and generic depression instruments. The performance of screening instruments was derived from a systematic review and bivariate meta-analysis at a range of instrument cut points; estimates of other relevant parameters were derived from literature sources and relevant databases. A decision tree considered the full treatment pathway from the possible onset of postnatal depression through identification, treatment, and possible relapse. Setting Primary care. Participants A hypothetical population of women assessed for postnatal depression either via routine care only or supplemented by use of formal identification methods six weeks postnatally, as recommended in recent guidelines. Main outcome measures Costs expressed in 2006-7 prices and impact on health outcomes expressed in terms of quality adjusted life years (QALYs). The time horizon of the analysis was one year. Results The routine application of either postnatal or general depression questionnaires did not seem to be cost effective compared with routine care only. The Edinburgh postnatal depression scale (at a cut point of 16) had an incremental cost effectiveness ratio (ICER) of £41 103 (€45 398, $67 130) per QALY compared with routine care only. The ICER for all other strategies ranged from £49 928 to £272 463 per QALY versus routine care only, while the probability that no formal identification strategy was cost effective was 88% (59%) at a cost effectiveness threshold of £20 000 (£30 000) per QALY. While sensitivity analysis indicated that the cost of managing incorrectly identified depression (false positive result) was an important driver of the model, formal identification approaches did not seem to be cost effective at any feasible estimate of this cost. Conclusions Formal identification methods for postnatal depression do not seem to represent value for money for the NHS. The major determinant of cost effectiveness seems to be the potential additional costs of managing women incorrectly diagnosed as depressed. Formal identification methods for postnatal depression do not currently satisfy the National Screening Committee’s criteria for the adoption of a screening strategy as part of national health policy.