Experts today challenge the view that popular drugs to prevent disease - like statins and antihypertensives to prevent heart disease and stroke, or bisphosphonates to prevent fractures - represent value for money.
In a paper published on bmj.com today, Teppo Järvinen and colleagues argue that the benefits seen when these drugs are tested in clinical trials may not apply in the real world.
They argue that value for money in real life clinical practice is likely to be much lower than in a clinical trial, where patients are carefully selected and receive special attention from dedicated staff. "This gap between the ideal and clinical circumstances raises the question of how well our most widely used preventive drugs work in real life," they write.
For example, data from randomised trials suggest that bisphosphonates are a cost effective way to prevent hip fractures in older people. But this is a far cry from reality, say the authors.
Using 2003 data on 7411 hip fractures in Finland, they estimate that giving bisphosphonates to all 1.86 million citizens aged 50 years and over would only guarantee prevention of 343 fractures.
"Thus, although there are claims that important preventive drugs such as statins, antihypertensives, and bisphosphonates are cost effective, there are no valid data on the effectiveness, and particularly the cost effectiveness, in usual clinical care," they say.
Despite this dearth of data, they point out that the majority of clinical guidelines and recommendations for preventive drug therapy rest on these claims.
The authors argue that before claims on cost effectiveness can be used to guide treatment policies and practices, it should be adequately proven by testing in a real-world setting.
"We need to put an end to this kind of gaming of the system and start to advocate true comparative effectiveness research," they conclude. "Unless this is done, the important question whether preventive pharmacotherapy is cost effective will remain unanswered."