Table 2.

Characteristics of patients and hospitals in studies that included specific patient populations

Study	Study population	Hospital type	Multicenter	Total sample size		Observed readmission rate (%)
				Derivation	Validation
Asche et al, 201625	18+ AMI patients	Academic and non-academic	Yes	3058	Fivefold cross validation	8.9
Benuzillo et al, 201826	18+ CABG patients	Academic and non-academic	Yes	1693	896	9.15
Cheung et al, 201827	18+ heart failure patients	Non-academic/large community	No	4711	2019 (validation and testing)	13
Eby et al, 201528	18+ type 2 diabetes patients	Academic and non-academic	Yes	52 070	Bootstrap resampling with 500 iteration	10
Flythe et al, 201629	18+ hemodialysis patients	Academic	No	349	Bootstrap resampling with 1000 iteration	32.1
Golas et al, 201830	18+ heart failure patients	Academic and non-academic	Yes	11 510	Bootstrap 10-fold cross validation	23
Hatipoglu et al, 201831	18+ pneumonia patients	Academic	No	1295	393	25
Horne et al, 201632	18+ heart failure patients	Academic and non-academic	Yes	Total: 6079	Total: 2663	14.1
				Female: 3013	Female: 1318	12.5
				Male: 3066	Male: 1334	16.5
					External total: 5162	15.6
					External female: 2537	14.6
					External male: 2625	18.6
Karunakaran et al, 201833	18+ type 2 diabetes patients	Academic	No	44 203	Split sample	20.4
Mahajan et al, 201834	18+ heart failure patients	VA health center	Yes	1210	Bootstrap 10-fold cross validation	21.7
Makam et al, 201735	18+ pneumonia patients	Academic and non-academic	Yes	1463	Fivefold cross validation	13.6
McGirt et al, 201536	18+ low back surgery patients	Academic	No	1803	361	5.9
Nguyen et al, 201837	18+ AMI patients	Academic and non-academic	Yes	826	Fivefold cross validation	13
Padhukasahasram et al, 201538	18+ heart failure patients	Non-academic/large community	No	789	10-fold cross validation	54.4
Reddy et al, 201839	18+ lupus patients	Academic and non-academic	Yes	9457	70:30 split	17.2
Rubin et al, 201640	18+ type 2 diabetes patients	Academic	No	26 522	17 681	20.4
Rubin et al, 201741	18+ type 2 diabetes patients admitted to hospital for cardiovascular conditions	Academic	No	4950	3219	20
Rumshisky et al, 201642	18+ psychiatric patients	Academic	No	3281	1406	22
Shameer et al, 201643	18+ heart failure patients	Non-academic/large community	No	748	320	16.6
Taber et al, 201544	18+ kidney transplant patients	Academic	No	1147	Bootstrap cross validation	11
Wang et al, 201624	18+ heart failure patients	Academic	No	4548	Bootstrap cross validation	33
Xiao et al, 201845	18+ heart failure patients	NA	NA	3000	67:16:16 split for training, validation, and testing	NA
Zheng et al, 201546	18+ heart failure patients	NA	NA	1641	Fivefold cross validation	19.3
Zolbanian et al, 201847	18+ heart failure patients	Academic and non-academic	Yes	Heart failure: 32 350; COPD: 31 070	70:30 10-fold cross validation	NA

AMI=acute myocardial infarction; CABG=coronary artery bypass graft; COPD=chronic obstructive pulmonary disease; NA=not available.