. 2018 Jun 28;8(6):e021161. doi: 10.1136/bmjopen-2017-021161

Table 1.

Studies investigating the link between continuity and mortality that meet the inclusion criteria, ordered by study design

First author and year of publication	Country of origin	Patients	Study design	Number of patients if cohort study	Continuity measure	Continuity with	Length of time continuity measured	Confounding factors checked and/or adjusted for	Mortality measure	Quality score (mean (of two reviewers)	Mortality primary outcome?	Length of time mortality counted
Bentler 2014¹³	USA	65 years+, community residing Medicare beneficiaries who completed NHHSUQ survey, not in managed care, not in MMC plan.	PC	1219	1, 2, 3, 5, 8	Physician	1–2 years	A,B,C,D,E,F,G, H,I,K,M,N,O	All-cause time to death	9	Yes	Up to 5 years
Cerovečki 2013¹⁴	Croatia	With opioid dependence, treated with methadone in family medicine setting.	PC	287	7	Family physician	12 years	A,B,M,O,S	All cause	8.5	Yes	12 years
Spatz 2014¹⁵	USA	18 years+, hospitalised with acute myocardial infarction.	PC	2454	8	Doctor	N/A	A,B,C,D,E,F,G, I,J,M,O,T	All cause	9	Yes	12 months
van Walraven 2010¹⁶	Canada	18 years+, discharged into community from medical or surgical services of 11 Ontario hospitals.	PC	3876	1	Physician who saw patient before, during and/or after hospital stay	6 months	A,B,H,L,N,O	All cause	9	Yes	6 months
Blecker 2014¹⁷	USA	18 years+, hospitalised at least 2 days including at least one at weekend.	RC	3391	1	Discharge physician	2 days	A,B,C,K,N,O,T	In hospital	8	No	Length of hospital stay
Brener 2016¹⁸	Canada	18 years+, discharged from hospital into community, family physician has history of hospital visits.	RC	164 059	9	Family physician	N/A	A,B,D,L,O,Q	All cause	9	Yes	90 days postdischarge
Hoertel 2014¹⁹	France	In CNAMTS insurance fund, saw a psychiatrist regularly.	RC	14 515	2	Psychiatrist	3.5 years	A,B,D,K,N,O	All cause	8.5	Yes	3 years
Justiniano 2017²⁰	USA	18 years+, underwent colorectal resection and readmitted within 30 days of DC.	RC	20 016	0	Surgeon	N/A	A,B,C,I,K,O, P,Q,T,U	All cause, colorectal cancer	9	Yes	1 year
Leleu 2013²¹	France	NHI reimbursement patients, >2 visits in 6 months.	RC	325 742	1, 2	Primary care physician/GP	3 years	A,B,D,K	All cause	9	Yes	3 years
Liao 2015²²	Taiwan	31–99 years, with type 2 diabetes.	RC	89 428	6	Any physician	1 year	A,B,H,K,N, O,P,U	All cause	8.5	No	4–9 years
Lustman 2015²³	Israel	40–75 years, with type 2 diabetes, remained in area, saw primary care provider >3x.	RC	23 679	1	Primary care physician/GP	2 years	A,D,H,K,M, N,O	All cause, diabetes related causes	8.5	Yes	2 years
Maarsingh 2016²⁴	The Netherlands	55–85 years, data available.	RC	1712	3	GP	17 years	A,B,D,E,F,G, K,M,Q,O	All cause	9	Yes	21 years
McAlister 2013²⁵	Canada	20 years+, DC from hospital with 1st time heart failure.	RC	16 855	0, 1	Physician who saw patient x2 in year before or 1x during admission	N/A	D,K,O,P,Q,R	All cause	9	Composite	3 months/6 months
McAlister 2016²⁶	Canada	20 years+, DC from hospital with 1st time heart failure.	RC	39 249	0,1	Any physician	N/A	A,B,Q,K,M, O,H	All cause	8	Composite	30 days
Pan 2017²⁷	Taiwan	35 years+, diagnosed with type 2 diabetes, in Taiwan NHI database.	RC	396 838	2	Any physician	8 years	A,B,D,K,O, P,Q	All cause	8.5	Yes	Up to 8 years
Shin 2014²⁸	South Korea	20 years+, in Korean National Health Insurance, new diagnosis of hypertension, diabetes, hypercholesterolaemia or their complications.	RC	47 433	2, 4, 5	Physician	2 years	A,B,D,F,K, N,Q,U	All cause	9	Yes	Up to 5 years
Sidhu 2014²⁹	Canada	‘Adults’ treated and released from 93 emergency departments with first-time diagnosis of heart failure.	RC	12 285	0, 1	Physician who saw patient x2 in year before or 1x during admission	30 days	A,B,G,K,O, P,Q,N	All cause	8.5	Composite	12 months but only give separate data for deaths for 30 days
Weir 2016³⁰	USA	20 years+, with incident diabetes and at least 2 years insurance.	RC	285 231	1	Physician who saw patient the most	2 years	A,B,D,G, H,K,O	All cause	8.5	Composite	1 year
Worrall 2011³¹	Canada	65 years+, with diabetes, 2+ fee-for-service family physician visits.	RC	305	1	Family physician	3 years	A,B,N	All cause	7	Yes	3 years
Baker 2016³²	England	Registered with 7858 general practices, with complete data, in England.	CS	N/A	8	GP	N/A	C,D,F,G,J,P	Premature- ratio observed to expected, age <75	8	Yes	N/A
Honeyford 2013³³	England	Registered with 229 general practices in the East Midlands between April 2006 and March 2009.	CS	N/A	8	GP	N/A	A,B,C,D,F, G,P,U	CHD under 75 and all age.	8	Yes	3 years
Levene 2012³⁴	England	18 years+, registered with GP for at least 6/12 months of the year.	CS	N/A	8	GP	N/A	A,B,C,D, F,O,P	All cause, COPD, all cancer, CHD	9	Yes	2 years

Continuity measures: 1, usual provider of care index; 2, continuity of care index; 3, Herfindahl-Hirschmann Index; 4, Modified, Modified Continuity Index; 5, most frequent provider; 6, % consistency to physician; 7, loss of contact with family physician; 8, patient survey; 9, family physician visited patient in hospital; 0, follow-up by familiar doctor.

Confounding factors: A, age; B, sex; C, race; D, deprivation/social status/income; E, education; F, smoking; G, chronic conditions; H, prior hospitalisation; I, insurance; J, acute conditions; K, co-morbidity (including Charlston Index); L, LACE Index (risk of 30-day readmission or death after hospital discharge); M, marital/relationship status; N, number of healthcare visits/service intensity; O, other healthcare history; P, practice, hospital or doctor characteristics; Q, location; R, length of hospital stay; S, treatment plan; T, timing of admission; U, other.

CS, cross-sectional; CHD, Coronary heart disease; CNAMTS, Caisse Nationale de l’Assurance Maladie des Travailleurs Salariés; COPD, Chronic Obstructive Pulmonary Disease; DC, discharged; GP, general practitioner; MMC, Medicare Managed Care; N/A, Not Applicable; NHHSUQ, National Health and Health Services Use Questionnaire; NHI, National Health Insurance; PC, prospective cohort; RC, retrospective cohort.