Table 5 Factors influencing variation in cost-effectiveness

Epidemiological environment

Prevalence of condition

Screening and referral programs for breast cancer

Incidence of condition

Preventive measures for many injuries

Existence of competing risks of synergisms

Some surgical interventions: among the very young or elderly, competing risks reduce the cost-effectiveness of some targeted interventions

Individual characteristics

Age

Cancer treatment: more cost-effective for younger patients

Tendency to compliance

Anti-hypertensive medication

Tendency to self-refer

Diabetes control

Level of risk factors

Hypertension and hyperlipdemia

Individual variation in values

Attitude toward disability relative to risk of death; can lead to individual differences in intervention effectiveness

System characteristics

Local costs of non-traded inputs to health care system

Real costs of care intensive interventions (such as hospitalisation after trauma) are low where wages are low, because most health care personnel are relatively immobile

Generalised systemic competence

Cost-effectiveness at the margin of some interventions in a system with a low level of professionalism and capacity may be much higher than in more developed systems

Discount rate

Where discount rates are high, interventions with payoffs well into the future (such as treatment of obesity) become relatively less attractive.