Design & Procedures - General Procedures
The investigators will directly compare 2 distinct models of intensivist coverage in the 2 participating ICUs in Winnipeg:
A) The standard model: A single intensivist staffs an ICU for 7 days. He/she will is present during daytime hours, and takes call from home afterwards. This is the current staffing paradigm in both participating ICUs.
B) The 24-7 in-house coverage model: 24-7 in-hospital coverage by an intensivist is enabled by splitting each 24 hour period into two shifts. There will, as in the standard model, be a single intensivist covering the ICU during the day shifts for one week. The day shift will run 8 am to 5:30 pm on weekdays, and 8 am to 3 pm on Saturday and Sunday. The night shift intensivist will arrive and take over at 5:30 pm on weekdays, and 3 pm on weekends and remain in the hospital until 8 am. Call rooms will be provided to allow the night shift intensivist to sleep, if the workload permits.
The interventional part of the study will last 32 weeks, comprising 4 blocks of 8 weeks each. It will run from October 2008 until June 2009. During each 8 week block, each ICU will be staffed under model A or B. Thus we will alternate the models: A-B-A-B in one ICU, and B-A-B-A in the other. This alternating design obviates the problem with historical controls; any nonrandom difference between the two staffing models should be seen to come and go in this design.
A variety of outcomes will be compared between the two intensivist staffing models. The primary outcome, which is the one for which the sample size analysis was performed, is the intensivists' burnout scores.
In order to avoid contamination between the staffing models, patients (and family participants) whose ICU stay is long enough to include time under both models will be excluded from analysis. Also excluded will be patients who are directly transferred from one ICU in Winnipeg to another. For patients who are admitted more than once to a participating ICU during the study, only the initial ICU admission will be included in the analysis.
The intensivists rotate on a weekly basis, and they will be provided questionnaires at the end of each week of ICU service. ICU nurses will be surveyed at the end of each 8 week block of a given staffing model. House officers in the ICU at HSC rotate on a 4 week basis, and they will be provided questionnaires at the end of their final week of their ICU rotations.
Even though the study design makes it likely (apart from the possibility of seasonal differences over the 32 weeks of the study) that participants' characteristics will be balanced between the two staffing models, this is not a randomized study and our primary analysis will use regression modeling to adjust for baseline characteristics of subjects. The investigators will use ordinary least squares or quantile regression for continuous variables, and logistic regression for binary variables. This approach permits assessment for differential effects between the two sites by including: (i) an indicator variable representing the separate sites, and (ii) interaction terms between that indicator variable and other covariates. A relevant aspect of the analysis is that outcomes for the intensivists, nurses and house officers derive from questionnaires, and that a single individual could complete the questionnaire more than once. Regression using General Estimating Equation methodology will therefore be used to account for correlation of responses within subjects.
Design & Procedures - Specific Aims Specific Aim#1: To compare clinical outcomes for ICU patients cared for under the two intensivist staffing models.
- The Department of Medicine has long maintained a comprehensive clinical database of all patients admitted to Winnipeg ICUs. It contains information about patients' demographics, illness type and severity, comorbid conditions, and ICU and hospital course, including the outcomes for this study. The investigators will obtain a deidentified data file containing this information for patients admitted to the participating ICUs during the study period.
Specific Aim#2: To compare family satisfaction with ICU care under the two intensivist staffing models.
- On each day for each of the participating ICUs, the investigators will attempt to recruit the next-of-kin of one newly admitted patient. The investigators will use a 2 stage consent process for these participants. The investigators will use the Family Satisfaction Survey - ICU 24 for assessing family satisfaction with care. This well-validated tool has two subscales, and has been extensively used in Canadian ICUs.
Specific Aim#3: To compare the work-related personal/emotional burden for intensivists working under the two intensivist staffing models.
- The intensivists will be asked to complete multiple questionnaires. Before starting, and after concluding the intervention, all Winnipeg intensivists will be surveyed. After each one week rotation, the intensivists who worked that week in the participating ICUs will be surveyed. A single consent provided before beginning the study intervention will ask the intensivists to consent for all the questionnaire that they will receive. The initial survey establishes background information, and asks for their opinions and preferences relating to the two different intensivist staffing models. The concluding survey repeats those questions. The weekly questionnaires contain the items for the 5 scales that will be analyzed; four of those scales are validated. The fifth scale, Role Conflict, aims to assess an interaction that only occurs in the shift work staffing model, i.e. the interface between 2 intensivists doing shift-work. The investigators were unable to find any scale that addresses this sort of issue, and thus created the items ourselves.
Specific Aim#4: To compare ICU nurses' perceptions of working alongside the two intensivist staffing models.
- At the end of each 8 week block of the study, we will ask all nurses in the participating ICUs to complete a questionnaire. The questionnaire asks for background information, about the mix of shifts they worked over the prior 8 weeks, and includes items from 5 validated scales.
Specific Aim#5: To compare ICU house officers' perceptions of working under the two intensivist staffing models.
- At the end of each 4 week rotation of ICU house officers in the Medical ICU at HSC, we will ask them to complete a questionnaire. The questionnaire asks for background information, the number of previous ICU rotations they completed, and items from 4 scales. The Autonomy and Role Conflict scales are validated. The Clinical comfort and Education/learning scales have been previously used, but have not been formally validated.
