Characteristics of studies included in the meta-analysis.

Abbreviations: BC, bladder cancer; C-C, case control; Co, cohort; NR, not reported; ACE: Acetaminophen; ASA: aspirin; NA-NSAIDs: nonaspirin NSAIDs.
*1, age; 2, sex; 3, residence; 4, certain occupations; 5, coffee drinking; 6, smoking; 7, socioeconomic status; 8, laxative intake, 9, education; 10, number of years employed as hairdresser/barber, 11, general practice; 12, duration of prescription history in the database; 13, index date; 14, body mass index, 15, race; 16, analgesic use; 17, period;18, fluid intake; 19, study; 20, physical activity; 21, history of heart disease; 22, stroke; 23, diabetes; 24, hypertension; 25, cholesterol-lowering drug use; 26, history of colorectal endoscopy; 27, family history of bladder cancer; 28, Hispanic status.