Identifying Non-Steroidal Anti-Inflammatory Drug (NSAID) Users Among People with Osteoarthritis Through Administrative and Clinician-Reported Data – A Validation Study of 116,162 Patients

Figures & data

Table 1 Demographics and Sample Characteristics by NSAID User Category

	OTC Users^a N:27,723 (24.7%)	Prescription Users^b N:21,190 (18.2%)	Non-Users with Dispensed Prescription^c N:7632 (6.6%)	Non-Users^d N: 58,617 (50.5%)
Sex, N (%)
Male	8033 (28.0%)	6274 (29.6%)	2522 (33.0%)	20,244 (34.5%)
Female	20,690 (72.0%)	14,916 (70.4%)	5110 (67.0%)	38,373 (65.5%)
Age, mean (SD)	64.9 (9.5)	63.8 (9.3)	65.5 (9.6)	67.9 (9.6)
Age groups
<60	7831 (27.3%)	6690 (31.6%)	1991 (26.1%)	10,654 (18.2%)
60–69	11,208 (39.0%)	8539 (40.3%)	2934 (38.4%)	20,540 (35.0%)
70–79	8304 (28.9%)	5220 (24.6%)	2231 (29.2%)	21,624 (36.9%)
80+	1380 (4.8%)	741 (3.5%)	476 (6.2%)	5799 (9.9%)
Affected joint, N (%)
Hip	8904 (31.0%)	6486 (30.6%)	2339 (30.6%)	18,635 (31.8%)
Knee	19,336 (67.3%)	14,419 (68.0%)	5087 (66.7%)	38,195 (65.2%)
Hand	469 (1.6%)	280 (1.3%)	199 (2.6%)	1738 (3.0%)
Shoulder	14 (0.0%)	5 (0.0%)	7 (0.1%)	49 (0.1%)
Pain 0–10, mean (SD)	5.6 (2.0)	6.0 (2.0)	5.7 (2.1)	5.2 (2.1)
Pain groups
Mild; NRS 0–4	7436 (25.9%)	4096 (19.3%)	1963 (25.7%)	19,846 (33.9%)
Moderate; NRS 5–7	16,153 (56.2%)	12,093 (57.1%)	4070 (53.3%)	30,313 (51.7%)
Severe; NRS 8–10	5134 (17.9%)	5001 (23.6%)	1599 (21.0%)	8458 (14.4%)
BMI, mean (SD)	27.7 (4.9)	28.4 (5.1)	28.0 (4.9)	27.3 (4.9)

Notes: ^aClinician-reported users without a dispensed prescription (false negatives); ^bClinician-reported users with a dispensed prescription (true positive); ^cClinician-reported non-users with a dispensed prescription (false positives), ^dClinician-reported non-users without a dispensed prescription (true negatives).

Abbreviations: OTC, Over The Counter; N, numbers; SD, Standard Deviation; NRS, Numeric Rating Scale; BMI, Body Mass Index.

Table 2 Prevalence of Reported NSAID Use and Psychometric Values of Dispensed NSAIDs in the 90 Days Preceding a First-Line Intervention to Identify People Reporting Use of NSAIDs

Sample	Sensitivity (95% CIs)	Specificity (95% CIs)	PPV (95% CIs)	NPV (95% CIs)	Prevalence of Clinician-Reported NSAIDs Users
All	42.5% (42.7%; 43.3%)	88.5% (88.2%; 88.7%)	73.5% (73.0%; 74.0%)	67.1% (66.8%; 67.4%)	43% (42.7%; 43.3%)
Pain strata (0/10 NRS scale)
Mild (0–4), N: 33.341	35.5% (34.6%; 36.4%)	91.0% (90.6%; 91.4%)	67.6% (66.4%; 68.8%)	72.7% (72.2%; 73.3%)	34.6% (34.1%; 35.1%)
Moderate (5–7), N: 62,629	42.8% (42.2%; 43.4%)	88.2% (87.8%; 88.5%)	74.8% (74.1% 75.5%)	65.2% (64.8%; 65.7%)	45.1% (44.7%; 45.5%)
Severe (8–10), N: 20,192	49.3% (48.4%; 50.3%)	84.1% (83.4%; 84.8%)	75.8% (74.7%; 76.8%)	62.2% (61.4%; 63.0%)	50.2% (49.5%; 50.9%)
Age strata (years)
<60, N:27,166	46.1% (45.3%; 46.9%)	84.3% (83.6%; 84.9%)	72.0% (71.4%; 72.6%)	77.1% (76.2% 77.9%)	57.6% (56.9%; 58.3%)
60–69, N:43,221	43.2% (42.5%; 43.9%)	87.5% (87.1%; 87.9%)	74.4% (73.6%; 75.2%)	64.7% (64.2%; 65.2%)	45.7% (45.2%; 46.2%)
70–79, N:37,379	38.6% (37.8%; 39.4%)	90.6% (90.3%; 91.0%)	70.1% (69.0%; 71.1%)	72.3% (71.7%; 72.8%)	36.2% (35.7% 36.7%)
>80, N: 8396	34.9% (32.9%; 37.0%)	92.4% (91.7%; 93.1%)	60.9% (58.1%; 63.6%)	80.8% (79.8%; 81.7%)	25.3% (24.3%; 26.2%)

Abbreviations: CIs, Confidence Intervals; PPV, positive Predictive Value; NPV, Negative Predictive Value; N, Number; NRS, Numeric Rating Scale.

Figure 1 Study flowchart.

Figure 2 Prevalence of NSAID use in the whole sample and in age and pain categories. Confidence intervals of the estimate can be found in the Supplementary File 2.

Figure 3 Prevalence of NSAID-user categories by calendar year. Confidence intervals of the estimate can be found in the Supplementary File 4.