Table 1.

Characteristics of Studies Identified in Literature Search

Source	Setting	No. enrolled	Study design	Years of accrual	Age range, years	Length of follow-up	Measures of comorbidity	Screening regimens compared	Outcome(s) of interest reported
Cohort studies
McPherson, 2002	USA	5186	Retrospective cohort	1986–1994	65–101	1 month to 10.9 years	Charlson Comorbidity Score	Mammographic vs. clinical (palpation) diagnosis	Risk of death
Fleming, 2005	USA	17,468	Retrospective cohort	1993–1995	≥67	--	24 conditions (listed in Table 4)	Diagnostic mammography vs. screening mammography	Late-stage (regional and distant) vs. early-stage (in situ and local) breast cancer
Yasmeen, 2012	USA	149,045	Prospective cohort	1998–2006	≥67	1–6 years	Unstable (life-threatening conditions such as severe heart failure, cardiac arrhythmias, end-stage liver disease), stable (conditions that could affect daily function such as diabetes, depression, arthritis, osteoporosis), or none	1-year interval vs. 2-year interval vs. 3-year interval vs. >3 years or first screening mammography vs. >3 years or first diagnostic mammography	Advanced- (stages IIB–IV) vs. early-stage (stages I–IIA) breast cancer
Braithwaite, 2013	USA	140,942	Prospective cohort	1999–2006	66–89	1–10 years	Charlson Comorbidity Score	1-year interval vs. 2-year interval	1. Invasive breast cancer vs. ductal carcinoma in situ (DCIS) 2. Advanced- (stages IIB–IV) vs. early-stage (stages I–IIA) breast cancer 3. Large (>20 mm) vs. small (≤20 mm) tumors 4. Lymph node involvement vs. no 5. False-positive recall 6. False-positive biopsy recommendation
Decision-analytic models
Mandelblatt, 1992	USA	--	Decision-analytic model	1975–1984	≥65	--	Average comorbidity (mortality equal to that of the general population), mild hypertension (mild comorbidity), congestive heart failure (major comorbidity)	Screening vs. no screening	1. Marginal savings in life expectancy 2. Long-term quality-adjusted marginal savings in life expectancy 3. Long- and short- term adjusted marginal savings in life expectancy
Messecar, 2000	USA	--	Decision-analytic model	--	≥75	10 years	Cognitive impairment vs. no cognitive impairment	One additional screening following regular biennial screening vs. no prior screening	Quality-adjusted savings in life expectancy
Lansdorp-Vogelaar, 2014	USA	--	Decision-analytic models	--	50–90	--	None, mild (history of myocardial infarction [MI], acute MI, ulcer or rheumatologic disease), moderate (cardiovascular disease, paralysis, diabetes), or severe comorbidity (AIDS, chronic obstructive pulmonary disease, mild/severe liver disease, renal failure, dementia, congestive heart failure)	Biennial screening from age 50 to cessation age ranging from 66 to 90	1. Incremental life-years gained (LYG) 2. Cancer deaths prevented 3. Incremental number of screening tests 4. False-positive screens 5. Over-diagnosed cases 6. Number needed to screen to gain one life-year (NNS/LYG) in the population