Economic evaluation of stepped-care versus usual care for depression and anxiety in older adults with vision impairment: randomized controlled trial

BACKGROUND: A stepped-care program was found effective in preventing depressive and anxiety disorders in older adults with vision impairment. However, before a decision can be made about implementation, the cost-effectiveness of this program should be investigated. Therefore, we aimed to compare the cost-effectiveness of stepped-care versus usual care within low vision rehabilitation.

METHODS: An economic evaluation from a societal perspective was performed alongside a multicenter randomized controlled trial. Data were collected by masked assessors during 24 months. Included were 265 older adults with vision impairment and subthreshold depression and/or anxiety. They were randomly assigned to stepped-care plus usual care (n = 131) or usual care alone (n = 134). Stepped-care comprised 1) watchful waiting, 2) guided self-help based on cognitive behavioral therapy, 3) problem solving treatment, and 4) referral to a general practitioner. Costs were based on direct healthcare costs and indirect non-healthcare costs. Main outcome measures were quality-adjusted life years (QALYs) and the cumulative incidence of major depressive, dysthymic and/or anxiety disorders. Secondary outcomes were symptoms of depression and anxiety.

RESULTS: Based on intention-to-treat, significant differences were found in the incidence of depressive/anxiety disorders (mean difference 0.17; 95% CI 0.06 to 0.29) and symptoms of anxiety (mean difference 1.43, 95% CI 0.10 to 2.77) in favor of stepped-care versus usual care; no significant difference was found for QALYs and symptoms of depression. Societal costs were non-significantly lower in the stepped-care group compared with the usual care group (mean difference: -€877; 95% confidence interval (CI): -8039 to 5489). Cost-effectiveness acceptability curves showed that the probability of cost-effectiveness was 95% or more at a willingness-to-pay of €33,000 per disorder prevented. The probability that stepped-care was cost-effective compared to usual care was 59% or more for a ceiling ratio of 0 €/QALY and increased to 65% at 20000 €/QALY.

CONCLUSIONS: This economic evaluation shows that stepped-care is dominant to usual care, with a probability of around 60%, due to its clinical superiority and its modest cost savings. However, it depends on the willingness-to-pay of decision makers whether or not stepped-care is considered cost-effective compared with usual care.

TRIAL REGISTRATION: identifier: NTR3296 , date: 13-02-2012.