Effect of different comorbid diseases on the risk of revision surgery (calculated using Cox regression analysis) after primary hip and knee replacement
| Comorbidity | Hip replacements | Knee replacements | ||||||
|---|---|---|---|---|---|---|---|---|
| Division of follow-up (years) | Univariate | Age- and sex-adjusted | Multivariate* | Follow-up (years) | Univariate | Age- and sex-adjusted | Multivariate* | |
| HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | |||
| Cardiovascular diseases | – | 1.09 (0.97 to 1.22) | 1.18 (1.05 to 1.32) | 1.19 (1.06 to 1.34) | – | 1.13 (1.01 to 1.26) | 1.29 (1.15 to 1.45) | 1.29 (1.14 to 1.45) |
| Coronary heart disease | – | 1.07 (0.94 to 1.22 | 1.15 (1.00 to 1.31) | 1.11 (0.94 to 1.28)† | – | 1.15 (1.02 to 1.31) | 1.30 (1.14 to 1.48) | 1.23 (1.07 to 1.41)† |
| Atrial fibrillation | – | 1.16 (0.97 to 1.40) | 1.22 (1.02 to 1.47) | 1.16 (0.96 to 1.41)† | – | 1.23 (1.03 to 1.47) | 1.35 (1.13 to 1.62) | 1.26 (1.04 to 1.51)† |
| Heart failure | – | 1.19 (0.96 to 1.48) | 1.35 (1.09 to 1.68) | 1.27 (1.01 to 1.59)† | – | 1.26 (1.02 to 1.56)† | ||
| Hypertension (without cardiovascular disease) | – | 1.04 (0.93 to 1.16) | 1.06 (0.95 to 1.18) | 1.09 (0.97 to 1.22) | 0–5 | 1.12 (1.00 to 1.25) | 1.11 (0.99 to 1.24) | 1.14 (1.01 to 1.29) |
| >5 | 0.80 (0.58 to 1.11) | 0.78 (0.57 to 1.07) | 0.84 (0.91 to 1.16) | |||||
| Diabetes | 0–5 | 1.08 (0.88 to 1.34) | 1.10 (0.89 to 1.35) | 1.03 (0.83 to 1.27) | 0–5 | 1.37 (1.16 to 1.61) | 1.38 (1.18 to 1.63) | 1.27 (1.08 to 1.50) |
| >5 | 0.61 (0.34 to 1.08) | 0.63 (0.36 to 1.12) | 0.60 (0.34 to 1.06) | >5 | 0.48 (0.23 to 1.01) | 0.49 (0.23 to 1.04) | 0.48 (0.22 to 1.01) | |
| Cancer | – | 1.28 (1.06 to 1.55) | 1.30 (1.08 to 1.57) | 1.27 (1.05 to 1.54) | 0–5 | 1.02 (0.82 to 1.27) | 1.10 (0.88 to 1.37) | 1.07 (0.86 to 1.34) |
| >5 | 1.98 (1.18 to 3.33) | 2.29 (1.36 to 3.88) | 2.21 (1.31 to 3.74) | |||||
| Pulmonary disease | – | 1.14 (0.96 to 1.35) | 1.14 (0.96 to 1.36) | 1.11 (0.93 to 1.32) | – | 1.22 (1.04 to 1.42) | 1.20 (1.02 to 1.40) | 1.13 (0.96 to 1.32) |
| Depression | 0–5 | 1.86 (1.31 to 2.64) | 1.83 (1.29 to 2.59) | 1.50 (1.02 to 2.21) | – | 1.86 (1.38 to 2.50) | 1.71 (1.27 to 2.31) | 1.33 (0.95 to 1.88) |
| >5 | 0.77 (0.29 to 2.06) | 0.75 (0.28 to 2.00) | 0.60 (0.22 to 1.63) | – | ||||
| Psychotic disorders | – | 1.56 (1.19 to 2.05) | 1.57 (1.19 to 2.06) | 1.41 (1.04 to 1.91) | – | 1.77 (1.39 to 2.25) | 1.67 (1.31 to 2.12) | 1.41 (1.07 to 1.86) |
| Neurodegenerative diseases | – | 1.25 (0.89 to 1.77) | 1.35 (0.96 to 1.91) | 1.28 (0.90 to 1.80) | – | 1.21 (0.88 to 1.67) | 1.40 (1.02 to 1.93) | 1.32 (0.95 to 1.82) |
For comorbidities for which the proportional hazards assumption of the Cox analysis was not met (ie, the hazard for revision surgery varied over the follow-up), the analyses were performed with division of follow-up, using the median as the cut-off point. In other cases, the hazards ratios are calculated for the whole follow-up. In univariate and age- and sex-adjusted models each comorbidity was tested separately. The multivariate model includes all comorbidities and the results indicate their independent effects.
*Multivariate model includes data on age, sex, operation year, laterality of operation (unilateral or simultaneous bilateral), method of prosthesis fixation and type of operating hospital (university hospital, central hospital, regional hospital, or other), in addition to comorbidity data.
†The hazards ratios are from a multivariate model in which cardiovascular diseases were replaced by the separate diseases.