Shukla 1983.

Methods	Non‐randomised trial
Participants	Patients admitted to 1 of 3 units (5 East = Primary Nursing; 3 East = Team Nursing; 5 West = Modular Nursing) during the study period.
Interventions	Interventions: Primary nursing: 100% RN; 1 nurse had direct and indirect responsibility for nursing care for a given number of hospital patients. Each nurse was assigned 4 to 6 patients for whom she had 24‐hour responsibility. RN delegated to associate nurses when off duty. Modular nursing: 50% RN, 50% LPN; a hybrid system under which 1 RN and 1 LPN provide cared for about 12 patients in one hospital area. The nurses were always assigned to the same modules to promote continuity of care. Control: Team nursing: 50% RN, 25% LPNs (licensed practical nurses), 25% aides; a group of RNs, licensed practical nurses, and nursing aides were led and directed by an RN, the team leader. Team usually consisted of 4 nursing staff, cared for 20 to 25 patients.
Outcomes	Quality of patient care Nurses' perception of quality Physicians' perception of quality Clinical care index Infection rate Costs: actual cost over study period per unit direct personnel costs total costs per patient day Nursing‐staff turnover
Country/Setting	US: Riverside Hospital, Virginia, major medical centre with 641 beds
Notes	Only objective outcomes were infection rate, costs and nursing‐staff turnover. Total number of participants or nurses was not reported. Partially supported by Grant 036501 from the National Center for Health Services Research, Medical College of Virginia, and Riverside Hospital, Newport News. No conflicts of interest reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Non randomised trial. Only 3 hospital wards included, 1 was experimental (3 East, Team Nursing), 1 was control (5 West, Primary Nursing), 1 was 'Modular' (hybrid) (5 East)
Allocation concealment (selection bias)	High risk	Allocation concealment was not possible with this design (no randomisation); furthermore, nurses chose to work in each of these settings (potentially biased towards the model of care).
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of personnel not possible. Possible that participants (patients) would not be aware of the intervention/control status, but they were a secondary consideration here.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Nurses reported infection rates.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Restricted to 2 outcomes relevant to the review: infection rates and costs;.both apparently reported in full.
Selective reporting (reporting bias)	Low risk	All outcomes appeared to be reported.
Baseline characteristics similar for intervention group and control?	High risk	Authors report baseline measurement was not possible as the units were already established. However, they reported the units were very similar and measured control variables ‐ staffing, workload and average RN competency ‐ over the study period to monitor the implementation of each intervention. However these data were only collected for 3 months of the data collection period.
Other bias	High risk	This was a very low‐quality study, a non‐randomised trial. There were no 'pre' measures. There was only 1 ward in each arm of the study. Most of the outcomes were not objective. While substantial effort was made to 'control' for variables (e.g. staff competency), the risk of bias for the participant nurses (who worked on each unit by choice) was very great. Statistics were difficult to follow ‐ e.g. the mean infection rates were tested by paired t‐tests, but t‐tests are not considered to be appropriate when there are 3 groups. Turnover rates were mentioned in the text, but were not reported in tables (and were not mentioned in the Methods).