Evaluating the impact of HTA and ‘better decision-making’ on health outcomes

Abstract: There is a lack of evidence concerning the link between HTA and outcomes in terms of health improvements. The international Decision Support Initiative (iDSI), a global partnership of HTA institutes, universities, and thinktanks, has developed a theory of change-based framework in order to evaluate the impact iDSI has on institutional strengthening – leading to ‘better decisions’ for ‘better health’. This framework recognises that there is a complex translation process between better decisions and better health dependent on many assumptions about local factors and systems, including linkage between decisions and budgets, delivery, implementation, and data accuracy. When those decisions result in implementation and practice change, then better health will be the result. Work has been undertaken to develop a methodological approach for measuring and better understanding the impact of HTA on the uptake of best practice on estimated (or measured) health outcomes. This involves synthesising economic methods with qualitative approaches, specifically a realist methodology which is becoming increasingly utilised in the evaluation of complex interventions. As such, we treat the process of HTA as a complex intervention which is intended to make a change, and would/should take different forms depending on purpose and context. As HTA works differently in different contexts - context being more than locality but embodies, for example, health care systems, resources and stakeholders - and impact is likely to be achieved through different change mechanisms, it is unlikely that the same intervention (ie HTA assessment and appraisal processes) can be replicated from one context to another and achieve the same outcomes. Good understanding about what works, for whom, in what contexts, and how – are, however, portable. We will develop and apply these methods to select aspects of iDSI’s work, with empirical testing - yet to be undertaken - using country case studies. We hope this might provide a better understanding as to how HTA needs to (better?) connect and interact with ‘context’ in translating into health outcomes so that the use of HTA can be optimised as well as understanding the value for money of HTA bodies.