An economic evaluation of targeted case-finding strategies for identifying postnatal depression:A model-based analysis comparing common case-finding instruments

BACKGROUND: Half of women with postnatal depression (PND) are not identified in routine care. We aimed to estimate the cost-effectiveness of PND case-finding in women with risk factors for PND. METHODS: A decision tree was developed to represent the one-year costs and health outcomes associated with case-finding and treatment for PND. The sensitivity and specificity of case-finding instruments, and prevalence and severity of PND, for women with ≥1 PND risk factor were estimated from a cohort of postnatal women. Risk factors were history of anxiety/depression, age < 20 years, and adverse life events. Other model parameters were derived from published literature and expert consultation. Case-finding for high-risk women only was compared with no case-finding and universal case-finding. RESULTS: More than half of the cohort had one or more PND risk factor (57.8 %; 95 % CI 52.7 %-62.7 %). The most cost-effective case-finding strategy was the Edinburgh Postnatal Depression Scale with a cut-off of ≥10 (EPDS-10). Among high-risk women, there is a high probability that EPDS-10 case-finding for PND is cost-effective compared to no case-finding (78.5 % at a threshold of £20,000/QALY), with an ICER of £8146/QALY gained. Universal case-finding is even more cost-effective at £2945/QALY gained (versus no case-finding). There is a greater health improvement with universal rather than targeted case-finding. LIMITATIONS: The model includes costs and health benefits for mothers in the first year postpartum, the broader (e.g. families, societal) and long-term impacts are also important. CONCLUSIONS: Universal PND case-finding is more cost-effective than targeted case-finding which itself is more cost-effective than not case-finding.