Table III.
Risk of selected exposures for subsets of symptomatic hand OA (n = 1076)
| Unclassified∗ | Erosive OA | Generalised hand OA | IPJ and thumb base OA | Thumb base OA | Nodal IPJ OA | Non-nodal IPJ OA | Likelihood ratio chi-square test | ||
|---|---|---|---|---|---|---|---|---|---|
| Previous hand injury | % (no.) | 28.8% (88) | 32.0% (16) | 24.8% (36) | 37.8% (31) | 34.1% (71) | 31.6% (24) | 31.4% (16) | |
| aRRR (95% CI) | 1 | 1.5 (0.7, 2.9) | 0.9 (0.6, 1.5) | 1.7 (1.0, 2.9) | 1.3 (0.9, 1.9) | 1.2 (0.7, 2.1) | 1.2 (0.6, 2.2) | χ2 = 6.4; P = 0.385 | |
| Excessive use of hands in employment or pastimes | % (no.) | 81.1% (258) | 84.0% (42) | 79.0% (120) | 86.9% (73) | 82.7% (177) | 85.5% (65) | 80.8% (42) | |
| aRRR (95% CI) | 1 | 1.7 (0.7, 4.0) | 1.1 (0.7, 2.0) | 1.9 (0.9, 3.9) | 1.2 (0.8, 2.0) | 1.6 (0.8, 3.2) | 1.1 (0.5, 2.3) | χ2 = 5.0; P = 0.540 | |
| BMI >30 kg/m2 | % (no.) | 37.5% (142) | 42.3% (22) | 39.0% (64) | 34.0% (33) | 33.9% (82) | 40.7% (33) | 37.3% (22) | |
| aRRR (95% CI) | 1 | 1.2 (0.7, 2.3) | 1.1 (0.7, 1.6) | 0.9 (0.5, 1.4) | 0.9 (0.6, 1.2) | 1.1 (0.7, 1.9) | 1.0 (0.6, 1.8) | χ2 = 2.7; P = 0.850 | |
| Diabetes/IFG | % (no.) | 6.3% (24) | 9.6% (5) | 13.4% (22) | 9.3% (9) | 7.0% (17) | 11.0% (9) | 5.1% (3) | |
| aRRR (95% CI) | 1 | 1.3 (0.4, 3.6) | 1.7 (0.9, 3.4) | 1.2 (0.5, 2.7) | 0.9 (0.5, 1.7) | 1.5 (0.7, 3.4) | 0.6 (0.2, 2.2) | χ2 = 6.1; P = 0.414 | |
| Hypertension | % (no.) | 26.3% (100) | 48.1% (25) | 40.9% (67) | 28.9% (28) | 35.1% (85) | 25.6% (21) | 32.2% (19) | |
| aRRR (95% CI) | 1 | 1.7 (0.9, 3.2) | 1.3 (0.9, 2.0) | 0.9 (0.5, 1.4) | 1.3 (0.9, 1.8) | 0.8 (0.5, 1.4) | 1.1 (0.6, 2.0) | χ2 = 8.2; P = 0.223 | |
| Dyslipidaemia | % (no.) | 21.1% (80) | 30.8% (16) | 20.1% (33) | 22.7% (22) | 25.2% (61) | 14.6% (12) | 23.7% (14) | |
| aRRR (95% CI) | 1 | 1.8 (0.9, 3.6) | 1.0 (0.6, 1.6) | 1.1 (0.6, 1.8) | 1.1 (0.8, 1.7) | 0.6 (0.3, 1.2) | 1.1 (0.6, 2.1) | χ2 = 7.0; P = 0.317 | |
| Metabolic syndrome† | % (no.) | 7.4% (28) | 15.4% (8) | 10.4% (17) | 7.2% (7) | 8.3% (20) | 6.2% (5) | 5.1% (3) | |
| aRRR (95% CI) | 1 | 1.7 (0.7, 4.1) | 1.1 (0.5, 2.2) | 0.8 (0.3, 1.8) | 0.9 (0.5, 1.7) | 0.7 (0.2, 1.8) | 0.5 (0.2, 1.9) | χ2 = 4.2; P = 0.650 |
Analysis was completed on CASHA and CASK study participants using mutually exclusive subsets as determined in Fig. 1; Likelihood ratio chi-square test indicates (overall) whether model fit was improved by having the risk factor in the model, statistical significance all of models were calculated to six degrees of freedom.
Individuals in this sub-group are symptomatic with pain in the last month and may have some radiographic changes, but they do not meet the criteria for any of the hand OA subsets.
Defined as three or more of the following factors: i) BMI >30 kg/m2, ii) diagnosis by general practitioner of diabetes or IFG, iii) hypertension, iv) dyslipidaemia (elevated triglycerides or cholesterol) or prescription of a lipid-regulating drug; aRRR, age/sex adjusted relative risk ratios; data was missing for the following exposures: previous hand injury n = 158 (14.7%), excessive use of hand in employment or pastimes n = 130 (12.1%), BMI >30 kg/m2n = 2 (0.2%) and metabolic syndrome n = 2 (0.2%).