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.