How long should treatments be continued?BMJ 2010; 341 doi: https://doi.org/10.1136/bmj.c4102 (Published 19 August 2010) Cite this as: BMJ 2010;341:c4102
- Jonathan C Craig, senior staff specialist, paediatric nephrology1,
- Angela C Webster, staff specialist, nephrology1,
- Clement Loy, staff specialist, neurology1
- 1Sydney School of Public Health, University of Sydney, Sydney NSW, Australia
To make evidence based decisions, clinicians and patients need to know the answers to three questions about an intervention. Does it do more good than harm? How intense should treatment be? For how long should it be given? In the linked study (doi:10.1136/bmj.c4024), Chen and colleagues tackle the third question by assessing relapse rates after a first episode of psychosis in patients who either continued or discontinued antipsychotic drugs after at least one year of treatment.1
Because of the explosion of randomised controlled trials and systematic reviews of trials in the past 50 years,2 we have high quality evidence on the effects of many interventions. These days, almost all issues of major general and specialist journals will include at least one randomised controlled trial that will provide reasonable certainty about the effects of a treatment. Implicit in the design will be the dose or intensity of the intervention evaluated, which is informed by previous phase I and II studies and may be the subject of specific phase III trials.
In comparison, we know little about how long interventions should be given, both for common acute conditions like respiratory or urinary tract infections,3 4 and for chronic conditions like mental illness, cardiovascular illness, and chronic …