Table 1.

Eligible studies included in the meta‐analysis

Lead author, Year	Country	Hospital location	Study design	Total patients or admissions	Total exposed to hypoglycaemia	People with diabetes (%)	Tytpe 1 diabetes	Type 2 diabetes	Treated with insulin (%)	Treated with oral agents (%)	Non‐exposed group	Adjustments during analysis	Hypoglycaemia definition (mmol/l)	Outcome
Gomez‐Huelgas, 2015 11	Spain	N/S	RCS	309 020	154 510	100	N/Sd	291 827	N/S	N/S	MP	Age, sex, type of diabetes, readmission, CCI, primary or secondary hypoglycaemia	ICD code	↑LOS, ↑ In‐hospital mortality
McEwan, 2015 12	UK	N/S	RCS	2158	1079	100	424	1734	100	0	MP	Age, sex, type of diabetes, use of medication, BMI, HbA1c, smoking, geographical region and CCI	ICD code	↑LOS, ↑In‐hospital mortalitya
Curkendall, 2009 13	USA	N/S	RCS	103 813	8234	100	5261d	87 610d	25.5	N/S	NM	Age, sex, type of diabetes, race, specific complications, events and conditions during hospitalizationd, CCI, insulin use, hospital characteristics and clinically plausible interactions	< 3.9	↑LOS, ↑In‐hospital mortality
Geremakis, 2014 14	USA	N/S	CCS	8952	2510	100	N/S	N/S	N/S	N/S	CC	Ethnicity, admitting hospital, CCI, surgery, fungal infection, antipsychotics, pulmonary hypertension, antidepressants, beta adrenergic, cephalosporin, antibiotics	<2.2	↑LOS
The NICE‐SUGAR Study Investigators, 2012 15	USA	ICU	SaRCT	6026	643	20	N/S	N/S	N/S	N/S	NM	Age, sex, APACHE II score, BMI, blood glucose, postoperative status, sepsis, trauma, diabetes, prior insulin or steroid treatment, cardiac failure, intensive vs. conventional insulin	≤ 3.9	↑Mortality within 90 days
Krinsley, 2007, 2011, 2017 8, 9, 10	USA	ICU	SaRCT	2786b	683	100	N/S	N/S	N/S	N/S	NM	Age, sex, APACHE II score, APACHE III score, mechanical ventilation	< 3.9	↑In‐hospital mortality
Sechterberger, 2013 16	Netherlands	ICU	RCS	10,320.	57	16	N/S	N/S	98	N/S	NM	Age, sex, APACHE II score, hypoglycaemia severity, cardiothoracic surgery, glucose variability, mean glucose, glucose levels ≤ 4.7 mmol/l	≤ 2.2	↑ICU mortality
Arabi, 2009 17	Saudi Arabia	ICU	NC	523	46	40	N/S	N/S	87	N/S	NM	Age, sex, BMI, postoperative status, APACHE II score, diabetes, admission glucose, mechanically ventilated, vasopressor, sepsis, creatinine, dialysis/filtration, intensive insulin	≤ 2.2	→ ICU mortality
Turchin, 2009 18	USA	General ward	RCS	4368 admissions	338 admissions	100	N/S	N/S	61.8% received insulin, OHA or both		NM for mortality. MP for LOS	Age, sex, ethnicity, health insurance, weighted mean daily glucose, LOS based on DRG and modified CCI	≤ 2.8	↑LOS ↑In‐hospital mortality
Ong, 2015 19	Singapore	General ward	RCS	288	54	100	N/S	N/S	91% received insulin, OHA or both		NM	Age, sex, ethnicity, BMI, HbA1c, number of comorbidities, systolic BP, admitting specialty, diabetes treatment, steroids and IV dextrose	<4.0	↑LOS
Borzi, 2016 20	Italy	General ward	SaCSS	3167	385	100	0	3167	N/S	N/S	NM	Age, sex, BMI, concomitant disease, insulin treatment, serum creatinine, HbA1c, fasting glucose and number of treatments other than diabetes	< 3.9	↑LOS ↑In‐hospital mortality
Nirantharakuma 2012 21	UK	General ward	RCS	6374 admissions	648 admissions	100	N/S	N/S	25	N/S	NM	Age, sex, ethnicity, deprivation, admission type, insulin use, modified CCI	< 3.9	↑In‐hospital mortality, ↑ LOSc
Kim, 2014 22	USA	General ward	RCS	1276 admissions	313	99	63d	1198d	0	100	NM	Age, sex, ethnicity, insulin use, CCI	≤ 3.9	↑LOS
Boucai, 2011 23	USA	General ward	RCS	31 970b	1717	34	N/S	N/S	19	11	NM	Age, sex, ethnicity, co‐morbidities, number glucose determinators, diabetes treatment	≤ 3.9	↑In‐hospital mortality, ↑LOS
Mellbin, 2008 24	Sweden	Cardiac speciality	SaRCT	1253	153	100	0	1253	N/S	N/S	NM	Age, sex, smoking status, previous myocardial infarction and coronary interventions, cardiac failure, pharmacological treatment, creatinine, diabetes duration, blood glucose before and during admission	< 3.0	→Total mortality (median follow up 2.1 years)

^aApplicable only to people with diabetes (not included in meta‐analysis as data not available).

^bData provided by author.

^cNot in meta‐analyses as only median data reported.

^dRemainder had unknown or undisclosed type of diabetes.

N/S, not specified; ICU, intensive care unit; RCS, retrospective cohort study; CCS, case controlled study; SaRCT, sub‐analysis of randomised control trial; NC, nested cohort within a RCT; SaCSS, sub‐analysis of two cross‐sectional studies; OHA, oral hypoglycaemic agents; MP, matched patients; NM, non‐matched; CC, case controlled; CCI, Charlson comorbidity score; DRG, diagnostic related group; LOS, length of stay.