Table 1.
Key methodologic elements of research protocol.
| Major category | Methodologic considerations | Details | Methodologic elements | ||
|---|---|---|---|---|---|
| 1. | Design | Research design | – | ● | Retrospective or historic cohort study |
| 2. | Population and sampling | Location | – | ● | Ten practice-based research networks across Canada; located in eight Canadian provinces: British Columbia, Alberta (two networks), Manitoba, Ontario (three networks), Quebec, Nova Scotia and Newfoundland and Labrador |
| Sampling | Sampling method | ● | Recruitment of PHC networks, sites, and providers; collection of patient data from the participating PHC providers | ||
| PHC setting | Sampling frame | ● | Consenting PHC networks, sites, and providers | ||
| Sampling method | ● | Non-random recruitment; based on interest in participating in CPCSSN dataset | |||
| Sampling size | ● | 82 PHC sites from 10 PHC networks | |||
| PHC providers | Sampling frame | ● | 39,392 family physicians [28] and 3,655 nurse practitioners in Canada in 2013 [29] | ||
| ● | Approximate total of 43,047 PHC providers in Canada in 2013 | ||||
| Sampling method | ● | Non-random recruitment; based on interest in participating in CPCSSN dataset | |||
| Sampling size | ● | 477 PHC providers recruited and contributing data | |||
| PHC patients | Sampling frame | ● | 35,345,000 population (and therefore potential PHC patients) in Canada in 2013 [30] | ||
| Sampling method | ● | Non-random collection of data; consistent and consecutive data collection | |||
| Sampling size | ● | 600,565 PHC patients included and contributing data | |||
| Rationale for sample size | – | ● | Utilized all eligible, adult patients included in the CPCSSN database | ||
| 3. | Data and definition | Data collection | Source of data | ● | Entire electronic medical record; provider documentation at each encounter |
| Method of data collection | ● | Extraction of de-identified and anonymized EMR data | |||
| Coding | Morbidity coding | ● | ICD-9 | ||
| Time | Time period of data source | ● | Length of EMR and ending on September 30, 2013 (date of data extract) | ||
| Length of recruitment period for patients for each PHC provider | ● | Recruitment began in 2008 and ended as of September 30, 2013 (date of data extract); length of retrospective data entered into the EMR system for each patient varied by PHC providers | |||
| Dates of data collection | ● | All data were extracted as of September 30, 2013 | |||
| Morbidity time focus | ● | Ever diagnosed in the EMR (lifetime morbidity) | |||
| Definitions | Definition of multimorbidity | ● | Two or more chronic disease diagnoses; creation of mutually exclusive categories of multimorbidity (patients with 2, 3, 4 and 5+ chronic disease diagnoses) | ||
| Definition of chronic diseases | ● | Chronic diseases were identified according to WHO definition of chronic and based on burden among populations; list of 20 chronic disease categories and corresponding ICD-9 codes are included in Table 2 | |||
| Operational definition of the count of chronic diseases | ● | PHC providers recorded diagnostic code during clinical encounter (not for research purposes); double counting was avoided by identifying the first chronic disease diagnoses of those chronic diseases on list | |||
| 4. Outcomes | Results | Outcomes reported | ● | Prevalence of single morbidity; prevalence of multiple morbidities; prevalence estimates stratified by relevant covariates; commonly occurring clusters of multiple chronic diseases; time-until-event information on both onset and advancing multimorbidity | |
| Confounders controlled | ● | Site characteristics (geographical location); provider characteristics (age, sex); patient characteristics (age, sex, residential geographic location) | |||
| Results presented | ● | Prevalence of multimorbidity; characteristics of adult patients living with multimorbidity; prognosis of multimorbidity over time | |||
CPCSSN, Canadian Primary Care Sentinel Surveillance Network; EMR, electronic medical record; ICD-9, International Classification of Disease, 9th Revision; PHC, primary healthcare; WHO, World Health Organization.