BackgroundThe NHS has recently undergone substantial restructuring, with Clinical Commissioning Groups (CCGs) taking the helm in purchasing health care for their local populations. This change takes place at a time when the NHS faces little to no predicted budgetary growth for the foreseeable future. The National Institute for Health and Care Excellence and Department of Health have called on commissioners to engage in disinvestment—the practice of stopping or restricting low-value health-care practices—and shifting resources to higher value care. This represents a cultural shift within the NHS. Little research has been invested into understanding how disinvestment works in practice. We aimed to: (a) investigate how local decision makers recognise and negotiate opportunities for disinvestment and (b) identify barriers to implementation of disinvestment decisions. MethodsWe did a qualitative study, adopting an ethnographic approach. Two NHS decision-making groups were followed up for 14 months through observations of routine meetings (n=8), and semistructured interviews with group members and front-line clinicians whose practice had been affected by disinvestment (n=28). Each decision-making group provided funding and disinvestment recommendations to Primary Care Trusts (PCTs) or CCGs for local implementation within two sociodemographically contrasting regions of England. Groups included health-care managers from PCTs, public health consultants, representatives from nascent CCGs, and local secondary-care providers. Interview participants were initially selected to include a range of professionals attending or affiliated with these meetings. Subsequent selection was guided by intentions to explore emerging themes from concurrent analysis. Meetings and interviews were audio recorded, transcribed, and thematically analysed using the constant comparison method. This was complemented by field notes taken during and after observations. A 10% sample of interview and meeting transcripts were independently analysed by two researchers to reduce researcher bias. Differences in coding and thematic interpretation were discussed face to face. We also emphasised searching for negative cases that conflicted with emerging themes or theories. Any conflicting cases were explicitly reported in findings. Key themes were compared by region and participants' commissioner or provider status. This study was granted full ethics approval by the Southampton South Central B panel. FindingsMeetings revealed few examples of active disinvestment decision making, with agendas dominated by requests for new health-care provision. Interviews revealed challenges in identifying opportunities for disinvestment, with previous approaches being unsystematic and unsustainable. A lack of capacity, methods, and training were key. Exploration of attempts to disinvest revealed differences in how commissioners and providers understood and portrayed disinvestment. This contributed to poor collaboration between these stakeholders. Providers sensed exclusion from previous disinvestment initiatives, which in their view compromised the clinical validity and acceptability of final decisions. All groups perceived a lack of central support for developing the disinvestment agenda. InterpretationOur findings support the urgent need for sustainable methods to guide local disinvestment practices. Crucially, disinvestment needs to be a collaborative effort, whereby health-care providers are included throughout the decision-making process. Some of our findings are limited because the study took place during a period of transition within the NHS; as such, observed practices may not have been as representative of standard practice as we would have liked. Nonetheless, interviews supported our interpretations of observed meetings, lending credibility to findings. As with most social research studies, there was potential for interview informants to produce socially desirable answers, which was partly accounted for by observing the same individuals' contributions and interactions in practice (ie, within observed meetings). Our findings support the need for research invested into developing and assessing methods to help commissioners identify and work through disinvestment processes. FundingNational Institute for Health Research.