Drugmakers are losing out on hundreds of billions of dollars as a result of patients not taking their medication.

That is the main finding of a report published by Capgemini Consulting and HealthPrize Technologies. The firms noted that based on detailed "review and analysis of modern claims-based adherence literature and data", the estimate of revenue lost by the US pharmaceutical industry each year due to not taking drugs for chronic disease is $188 billion. Extrapolated to the global sector, revenue losses are estimated to be $564 billion.

The report notes that this number is significantly higher than the $30 billion global loss often quoted to date from a 2004 study, "and higher than many pharmaceutical executive estimates". Indeed, the loss represents 59% of all pharma revenues, which were $320 billion in the USA and $956 billion globally in 2011 according to IMS figures.

Non-adherence is a problem across almost all chronic conditions, not only for diabetes, hypertension, and high cholesterol, but also for HIV, oncology, transplant, and glaucoma. In the US diabetes market alone, revenue loss is estimated to be $11.4 billion.

Thomas Forissier, principal at Capgemini Consulting, said that many people "don't realise that a 10% boost in adherence could increase revenue by much more than 10%. That 10% loss is based on the higher revenue amount that could have materialised, not on actual revenue earned".

Katrina Firlik, chief medical officer of HealthPrize, which uses gaming, behavioural economics and "proven concepts from consumer marketing" to educate patients on adherence, said that not taking medicine "is one of the most serious problems in healthcare, posing a heavy financial impact on all constituencies". She added that "given the significant potential to enhance revenue and lower cost to the overall healthcare system, programs to address medication adherence should be a top priority to the pharmaceutical industry".