Table 2.

Populating the preliminary set of methodological considerations “Methods Crystals for MM” with three examples

Major categories	Considerations	Details	Saguenay study	BEACH substudy	DELPHI study
–	–	–	Fortin et al. 20055	Britt et al. 20086; Knox et al. 20087	Stewart et al. 20094,8
1. Design	Research design:	–	Retrospective cohort study	Cross-sectional study	Retrospective cohort study
2. Population and sampling	Location:		Regional: Saguenay region, Quebec, Canada	National, Australia	Regional, South-western Ontario, Canada
	Sampling	Sampling method	Two-stage sampling: first of FPs, and then of their patients.	Two-stage sampling: first of FPs, and then of their patients.	Two-stage sampling: first of FPs, and then of their patients.
	Primary care setting(s)	Sampling frame	Not applicable (N/A), as study did not sample by practice.	N/A, as study did not sample by practice.	N/A, as study did not sample by practice.
		Selection method	N/A, as study did not sample by practice.	N/A, as study did not sample by practice.	N/A, as study did not sample by practice.
		Sample size	N/A	N/A	N/A
	Family practitioners (FPs)	Sampling frame	All FPs in region with a general practice in a doctors’ office or an institution, with accessible medical records, for adult patients of all ages.	All practicing FPs in Australia.	All FPs in south-western Ontario not using electronic medical records in 2005.
		Selection method	Contacted all FPs in sampling population for recruitment.	Random.	Non-random; FPs who agreed to participate in the DELPHI project.
		Sample size	21	305	25
	Patients	Sampling frame	Visiting patients ≥18 years old.	Visiting patients of all ages.	Visiting patients of all ages.
		Selection method	Consecutive.	Consecutive, 30 of the 100 patients per FP in the BEACH Programme9	Random selection of one patient per day, and patients followed up prospectively.
		Sample size	980	9156	2998
	Rationale for sample size	–	Not stated.	Not stated.	Recruitment ended after ~10% of all patients in FP’s practice were selected.
3. Data and Definition	Data collection:	Source of data	Whole medical record reviewed by a trained nurse.	Whole medical record, FP knowledge, provider documentation at visit, patient self-report.	Coding by FP at each visit.
		Method of data collection	Chart audit.	FP form.	Electronic medical record.
	Coding:	Morbidity coding	No coding.	Coding with nomenclature, classified to the International Classification of Primary Care (ICPC-2).10	Coding with ordering principle ICPC-2-R.11
	Time:	Time period of data source	Length of medical record.	Length of medical record.	Two years of medical record.
		Length of recruitment period for patients for each FP	2–3 weeks.	Several days.	6–12 months.
		Dates of data collection	December 2002–July 2003.	July–November 2005.	March 2006–February 2008.
		Morbidity time focus	Lifetime	Conditions currently under medical management	Conditions currently under medical management
	Definitions:	Definition of multi-morbidity	Two or more chronic conditions.	Condition(s) in two or more morbidity domains of the Cumulative Illness Rating Scale (CIRS).12	Two or more chronic conditions.
		Definition of chronic conditions	Conditions identified by chart auditors as meeting the World Health Organization’s (2002) definition of chronic conditions: ‘health problems that require ongoing management over a period of years or decades’.13	A selected list of 22 common cardiovascular, psychological, respiratory, musculoskeletal, endocrine problems and malignant neoplasms; classified in ICPC-210 and then mapped to eight domains in the CIRS and a separate domain for malignant neoplasms.	List of 98 ICPC-2-R12 codes, 85 defined as chronic conditions by Lamberts and Okkes11 and 13 codes added by DELPHI study investigators.
		Operational definition of the count of chronic conditions	Nurse judgement to document evolving or similar diagnoses as one condition.	FP judgement to document evolving or similar diagnoses as one condition.	FP to document each encounter, whereby evolving or similar diagnoses could be counted as several conditions.
4. Outcomes	Results	Outcomes reported	Prevalence of multi-morbidity.	Prevalence of multi-morbidity.	Prevalence of multi-morbidity.
		Confounders controlled	None. The region’s residents were compared with the rest of Canada by socio-economic status, age, educational level, median household income and unemployment rate.	Results adjusted by age and sex to the general practice patient population in 2005 and weighted to adjust for visit frequency. Study population compared with the overall Australian population, and a national population prevalence calculated.	Age and sex of all patients compared with those of the remaining people of Canada.
		Results presented	Prevalence of multi-morbidity by age and sex.	Prevalence of multi-morbidity by condition, age and sex.	Prevalence of multi-morbidity by age and sex.

BEACH, Bettering the Evaluation and Care of Health programme in Australia (2008); and DELPHI, Deliver Primary Health Care Information.