The effect of hypoglycaemia during hospital admission on health-related outcomes for people with diabetes: a systematic review and meta-analysis

Aims: To assess the health-related outcomes of hypoglycaemia for people with diabetes admitted to hospital; specifically, hospital length of stay and mortality.Methods: We conducted a systematic review and meta-analysis of studies relating to inpatient hypoglycaemia (<4 mmol/L) for hospitalised adults (≥16 years) with diabetes reporting the primary outcomes of interest, hospital length of stay or mortality. Final papers for inclusion were reviewed in duplicate and the adjusted results of each were pooled, using a random effects model then undergoing further prespecified subgroup analysis.Results: 15 studies were included in the meta-analysis. The pooled mean difference in length of stay for ward-based inpatients exposed to hypoglycaemia was 4.1 days longer (95% confidence interval [CI], 2.36-5.79; IÇ = 99%) compared to inpatients without hypoglycaemia. This association remained robust across the pre-specified subgroup analyses. The pooled relative risk (RR) of in-hospital mortality was greater for inpatients exposed to hypoglycaemia 2.09 (95% CI, 1.64 to 2.67; IÇ = 94%, n=7 studies) but not in intensive care unit mortality RR 0.75 (0.49 to 1.16; IÇ =0%, n=2 studies).Conclusion: There is an association between inpatient hypoglycaemia and longer length of stay and greater in-hospital mortality. Studies examining this association were heterogenous in terms of both clinical populations and effect size, but the overall direction of the association was consistent. Therefore, glucose concentration should be considered a potential tool to aid the identification of patients at risk of poor health-related outcomes.