Safety of the reuse of needles for subcutaneous insulin injection: A systematic review and meta-analysis

ObjectiveMany people with diabetes often reuse disposable needles for subcutaneous insulin injection. We aimed to identify, critically appraise and summarize the available evidence about the safety of this practice.DesignSystematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.Data sourcesMEDLINE (via PubMed), CINALH (via EBSCO), SCOPUS, Web of Science, Cochrane Central Register of Controlled Trials and Open Grey were searched from their inception to December 2015, with no language restrictions.Review methodsEpidemiologic and experimental studies assessing adverse effects of reusing needles in people of any age or sex, with or without diabetes, were included. Two reviewers independently assessed the methodological quality of included studies using a multi-design tool.ResultsIn total, 25 studies were included. All studies had a high risk of bias and data from only nine studies could be pooled. Five studies showed no association between infection at site of injection and reuse of needles (risk difference = −0.00; 95% confidence interval = −0.12–0.11; P = 0.99); heterogeneity between these studies was substantial (I2 = 66%; P = 0.02). Five cross-sectional studies showed an association between lipohypertrophy and needle reuse (risk difference = 0.16, 95% confidence interval = 0.05–0.28, P = 0.006); there was strong evidence of heterogeneity between these studies (I2 = 87%; P < 0.001). Pooled data of two studies with no evidence of heterogeneity between them showed more perceived pain among reusers (risk difference = 0.24; 95% confidence interval = 0.06–0.43; P = 0.006). Reusing a pen needle or disposable syringe-needle was not associated with worse glycaemic control.ConclusionsThere is currently no clear scientific evidence to suggest for or against the reuse of needles for subcutaneous insulin injection. This practice is very common among people with diabetes; consequently, further research is necessary to establish its safety.