What health technology assessment is and where it came from
Health technology assessment uses explicit, multidisciplinary methods to determine a technology's value and inform an equitable, efficient and high-quality health system. It encompasses clinical and economic evidence and mainly supports population decisions, while also informing choices for individual patients.
Definition and scope
Health technology assessment determines a technology's value at different points in its lifecycle through explicit, multidisciplinary methods. Its purpose is to inform decisions that promote an equitable, efficient and high-quality health system. A technology can be a medicine, device, surgical procedure, prevention programme or system for organising care.
Assessment includes clinical and economic evaluation and is mainly relevant to population-level decisions. It can also support shared decisions in which clinicians discuss clinical and economic evidence with patients, particularly where patients face co-payments. Its reach includes macro policy decisions about structures and oversight, meso decisions about organisations, and micro decisions about individuals' roles and behaviour. For medicines and biologics, payers and policy makers use safety, efficacy and economic information to decide access and reimbursement.
Related evidence activities
Evidence-based medicine combines clinicians' knowledge with published research evidence. By 2021, medical decision making had shifted over the preceding fifty years toward more systematically generated evidence and a greater population-level role for clinicians.
Three questions distinguish assessments of an intervention: efficacy asks whether it can work under ideal conditions; effectiveness asks whether it works in practice; efficiency asks whether it is worth the cost. Evidence-based medicine, comparative effectiveness research and HTA overlap but differ in emphasis along these questions and in their focus on generating evidence, synthesising it or making decisions.
Comparative effectiveness research compares alternatives to help patients, clinicians, purchasers and policy makers make informed decisions. Descriptions differ in scope:
- In 2015, it was described as asking which of two available treatments is more effective.
- A 2017 glossary described comparisons in real-world settings rather than controlled trials, covering benefits, harms and sometimes costs.
- In 2021, US usage encompassed effectiveness studies including pragmatic trials and registry and administrative-database analyses, usually excluding costs.
Origins and development
Technology assessment began at the US Office of Technology Assessment in the 1970s, including a health programme motivated by rising costs, inefficiency and the desire for better care. Its report on technology efficacy and safety stressed evidence as the basis for widespread use. HTA spread to Europe in the 1970s, with Sweden an early adopter.
Archie Cochrane's 1972 book, Effectiveness and Efficiency: Random Reflections on Health Services, helped underpin subsequent HTA development by advocating comparisons of alternatives' benefits and costs. His experience as a wartime medical officer and in the illnesses of South Wales coal miners led him to regard randomised trials as the only reliable evidence of whether his treatments did more good than harm. He also recognised that limited resources, including a doctor's time, meant that serving one patient could reduce what was available to others.
By 2021, HTA was practised across many countries, with differences in its use and methods. Its multidisciplinary definition was developed collaboratively by representatives of INAHTA, HTAi, ISPOR, EUnetHTA, HTAsiaLink, RedETSA and the HTA Glossary Committee.