The research, led by Queen Mary University of London, was conducted among patients with schizophrenia, schizoaffective disorder or bipolar disorder, who were prescribed long-acting antipsychotic injections but had received 75% or less of their recommended treatment.
They found that average adherence to treatment for patients who were offered £15 for each injection over a 12-month period increased by 16%, while those in the control group only rose by 4% over the same period.
Clinicians gave the monetary incentive in cash directly to patients after each injection, and patients signed a receipt. The sum of £15 was chosen because a fixed sum per injection simplifies the practice, is below the limit of £20 per week over which there would be interference with patients’ entitlements to disability benefits, and it was considered an important incentive without inducing financial dependency.
Vital to explore methods to improve adherence
Study lead Stefan Priebe, professor of social community & psychiatry at Queen Mary University of London (Barts and The London School of Medicine and Dentistry), said the figures show offering a modest financial incentive to patients with psychotic disorders is an effective method for improving adherence to treatment but not a 'cure-all' for anyone with problematic treatment adherence.
"The idea of using financial incentives to encourage patients with severe mental illness to take their medication regularly is controversial and has been widely debated from both a practical and ethical standpoint – but there is no denying it works," said Priebe.
"In lots of areas of medicine it doesn’t make too much difference if a patient misses a certain proportion of prescribed medication. However, among patients with severe mental illness, just missing one or two doses of antipsychotic drugs poses a high risk of relapse. This is why it’s so vital to explore alternative methods of improving adherence to mental health treatment – many mainstream methods so far have been tried and failed."
Increased rates of readmission
Poor adherence to antipsychotic drugs is a major problem in patients with psychotic disorders and is linked to increased rates of readmission to hospital and high treatment costs. Between 25% and 80% of patients fail to take their drugs correctly at some point in their treatment and poor adherence can treble the costs of external services.
It was also notable that patients in the intervention group reported a significantly more favourable subjective quality of life during the 12-month trial although other factors, such as the psychological effect of having extra money, could have also made an impact.
Yet Professor Priebe believes the question of using financial incentives often remains an ethical rather than medical consideration.
"Further research is needed to test the longer-term impact of offering financial incentives," he added. "In addition, we must continue looking into the psychological mechanisms that can give insight into the positive effects of offering financial incentives – not only on treatment adherence but on subjective quality of life."