If inequities exist, interventions are required to tackle the problem; the cycle being repeated to see whether interventions were effective.
Consequently, there exists an intervention between action of disease-causing rules and action of drug-induced rules.
Effective smoking cessation interventions exist, but interventions are needed to address these other risk factors.
Therefore the possibility exists that interventions may not be universally popular with caregivers and that caregivers are leaving interventions for reasons that are counterintuitive and hidden.
8 17 18 Consequently, a need exists for interventions that provide pain relief without risking adverse effects.
Whilst evidence on cost-effectiveness is lacking, a perception exists that interventions involving trained but unqualified peer or lay advisers are cheaper than those involving health professionals.
Whilst much is known about the epidemiology of suicidal behaviour, less evidence exists regarding interventions to reduce risk [ 8], particularly that from randomised-controlled trials [ 9].
Without a historical control, it was not possible to establish whether differences (or similarities) between contemporaneous controls and interventions existed before the intervention, or result from the intervention.
The benefits, risks, burdens and effectiveness of a new intervention must be tested against those of the best proven intervention(s), except in the following circumstances: Where no proven intervention exists, the use of placebo, or no intervention, is acceptable.
