Long-term cost-utility analysis of family therapy vs. treatment as usual for young people seen after self-harm

The joint evidence of the cost and the effectiveness of family-based therapies is modest. To study the cost-effectiveness of family therapy (FT) versus treatment-as-usual (TAU) for young people seen after self-harm combining data from an 18-month trial and hospital records up to 60-month from randomisation. We estimate the cost-effectiveness of FT compared to TAU over 5 years using a quasi-Markov state model based on self-harm hospitalisations where probabilities of belonging in a state are directly estimated from hospital data. The primary outcome is quality-adjusted life years (QALY). Cost perspective is NHS and PSS and includes treatment costs, health care use, and hospital attendances whether it is for self-harm or not. Incremental cost-effectiveness ratios are calculated and deterministic and probabilistic sensitivity analyses are conducted. Both trial arms show a significant decrease in hospitalisations over the 60-month follow-up. In the base case scenario, FT participants incur higher costs (mean +£1,693) and negative incremental QALYs (-0.01) than TAU patients. The associated ICER at 5 years is dominated and the incremental health benefit at the £30,000 per QALY threshold is -0.067. Probabilistic Sensitivity Analysis finds the probability that FT is cost-effective is around 3 − 2 • Extension of evidence base of hospitalisations from 18 months to 5 years show all hospitalisations and self-harm hospitalisations continue to decline with no incremental difference in performance between family therapy and treatment as usual. • The conditional cost of a self-harm hospitalisation falls in line with the probability of an hospitalisation. This suggests the constant conditional cost assumed by NICE may be unrealistic. It does not influence the health economic argument in this case but may well do where there is a difference in the rate of hospitalisations across treatments. • Out of hospital costs represent the main cost-driver and we are unable to estimate the longer-term relationship. Although this is unlikely to have any impact in this evaluation it remains an important research question. Similarly, the relationship between health-related quality of life and self-harm remains uncertain with smaller than anticipated differences measured when using self-harm hospitalisations.