Table 1. Definitions of variables used in the analysis.

Variable	Definition
NSAID classes a
Arylacetic acids	Diclofenac (100), Etodolac (400), Indomethacin (100), Sulindac (400), Tolmetin (700), Zomepirac (300)
Butylpyrazolidines	Phenylbutazone (300)
Fenamates	Floctafenine (1000), Mefenamic Acid (1000)
Oxicams	Meloxicam (15), Piroxicam (20)
Propionates	Fenoprofen (1200), Flurbiprofen (200), Ibuprofen (1200), Ketoprofen (150), Nabumetone (1000), Naproxen (500)
Coxibs	Celecoxib (200), Rofecoxib (20)
Aspirin (3000)
Screening
SCREENED	Binary variable with 1 indicating whether at any point prior to the index date a subject had a physician visit for BPH (ICD-9 code 600.*), prostatitis (601.*) or “other disorders of prostate” (602.*); or any point during the 11 years prior to the index date, a subject received at least one prescription for finasteride or an α-blocker or had prostatic ablation or resection, or testing of prostatic secretions. We assumed the men who received these services had at least a DRE.
Medical conditions b
Diabetes	≥2 physician claims with ICD-9 = 250
Hypertension	≥2 physician claims with ICD-9 = 401, 405 OR ≥2 prescriptions for selective β-blockers; thiazides; CCBs-DH; or centrally acting anti-adrenergics
Rheumatoid arthritis	≥2 physician claims with ICD-9 = 714 OR ≥2 prescriptions for DMRDs or steroids
Osteoarthritis	≥3 physician claims with ICD-9 = 710–713; 715–739; No DMRD or steroids
Other inflammatory arthritis	≥3 physician claims with ICD-9 = 710–713; 715–739 AND ≥1 DMRD or steroids
Cardiac disease/stroke	≥3 physician claims with ICD-9 = 390–400;402–404;406–459
GI bleeding	≥1 physician claims with ICD-9 = 578
Prostatic hypertrophy	≥1 physician claims with ICD-9 = 600 OR ≥1 prescriptions for finasteride or α-blockers OR ≥1 TURP or ablation
Prostatitis	≥1 physician claims with ICD-9 = 601 OR ≥1 physician claims for MEPS.
Others
Income status	Binary variable with 1 indicating ever having a prescription flagged for receiving income security benefits.
Vasectomy, TURP, Prostatic biopsy, MEPS	Information on these procedures was extracted from a list of all physician-provided urological services (services for which a physician claimed a fee-for-service code under section R of the Saskatchewan Ministry of Health’s “Payment Schedule for Insured Services Provided by a Physician”) since January 1, 1975.
Classes of medications	Prostatism agents, androgen antagonists, Lipid lowering agents, Angiotensin converting enzyme inhibitors, Angiotensin receptor blockers, α- and β-blockers, Antihypertensive calcium channel blockers, Centrally acting antihypertensives, Vasodilators, Diuretics, DMRDs, Systemic steroids, Anticoagulants, Cardiac glycosides, Proton pump inhibitors, H2 receptor antagonists, Other ulcer-healing agents. All drugs were classified according to the WHO ATC classification (see text).

a) For each NSAID, the WHO’s defined daily dose (DDD) used in the analysis is listed in parenthesis (in milligrams). The DDD is “the assumed average maintenance dose per day for a drug used for its main indication in adults”(WHO Collaborating Centre for Drug Statistics Methodology, 2002). Using DDDs, we effectively weighted the prescribed quantity of each NSAID by its anti-inflammatory potency.

b) Based on the most valid chronic disease identification algorithms (those algorithms with the highest Kappa and Youden’s index values) from a comprehensive review of the literature performed by Lix et al (20).

BPH: Benign prostate hypertrophy; CCBs-DH: Calcium channel blockers, dihydropyridine; DMRD: Disease-modifying anti-rheumatic drugs; DRE: Digital rectal examination; GI: Gastro-intestinal; MEPS: Microscopic examination of prostatic secretions; TURP: Transurethral resection of prostate.