Is Lean sustainable in today's NHS hospitals? A systematic literature review using the meta-narrative and integrative...

Methodological variance and quality, heterogeneity of value and divergent approaches are reasons for the varied results of Lean interventions in healthcare despite ongoing global popularity. However, there is piecemeal evidence addressing the sustainability of initiatives-the aim of this review is to use an integrative approach to consider Lean's sustainability and the quality of available evidence in today's National Health Service (NHS).

A literature review of AMED, CINAHL, Cochrane, JBI, SCOPUS, DelphiS, MEDLINE, EMBASE, MIDIRS, Web of Science and PsycINFO electronic databases was conducted.

Peer-reviewed studies in NHS hospitals/trusts that concerned undiluted, service-wide Lean adoption and contained quantitative data were included. Reference lists were consulted for evidence via a snowball approach. Methodological quality was assessed using an adapted critical appraisal tool.

Research design, method of intervention, outcome measures and sustainability were extracted.

Electronic searches identified 12 studies eligible for inclusion. This comprised of five quasi-experimental designs (one mixed-method), three multi-site analyses, one action research, one failure mode and effects analysis, one content analysis of annual reports and one systematic review. Six articles considered sustainability with two of these providing measured successes. Despite diverse and positive outcomes studies lacked scientific rigour, failed to consider confounding issues, were at risk of positive bias and did not demonstrate sustainability with any statistical significance.

Lean has ostensible value but it is difficult to draw a conclusion on efficacy or sustainability. Higher quality scientific research into Lean and the effect of staffing cultures on initiatives are needed to ascertain the extent that Lean can affect healthcare quality and subsequently be sustained.