Table 3. Determinants of variance in the incidence rates of hysterectomy across 54 Swiss HSAs.
| Model 1* | Model 2† | Model 3‡ | Model 4# | Model 5& | ||
|---|---|---|---|---|---|---|
| Incidence rate ratio (95%CI)§ | ||||||
| Case year | 2013 | Reference | Reference | Reference | Reference | Reference |
| 2014 | 0.98 (0.96–1.01) | 0.98 (0.96–1.01) | 0.99 (0.96–1.01) | 0.98 (0.96–1.01) | 0.98 (0.96–1.01) | |
| 2015 | 0.96 (0.93–0.98) | 0.96 (0.93–0.98) | 0.96 (0.93–0.99) | 0.95 (0.92–0.98) | 0.95 (0.92–0.98) | |
| 2016 | 0.94 (0.91–0.97) | 0.94 (0.91–0.97) | 0.94 (0.92–0.97) | 0.94 (0.91–0.97) | 0.94 (0.91–0.97) | |
| Age | 18–49 | 0.62 (0.61–0.64) | 0.62 (0.61–0.64) | 0.62 (0.61–0.64) | 0.62 (0.61–0.64) | |
| 50–54 | Reference | Reference | Reference | Reference | ||
| 55–59 | 0.54 (0.52–0.57) | 0.54 (0.52–0.57) | 0.54 (0.52–0.57) | 0.54 (0.52–0.57) | ||
| 60–64 | 0.51 (0.48–0.53) | 0.51 (0.48–0.53) | 0.51 (0.48–0.53) | 0.51 (0.48–0.53) | ||
| 65–69 | 0.54 (0.51–0.56) | 0.54 (0.51–0.56) | 0.54 (0.51–0.56) | 0.54 (0.51–0.56) | ||
| 70–74 | 0.52 (0.49–0.54) | 0.52 (0.49–0.54) | 0.52 (0.49–0.54) | 0.52 (0.49–0.54) | ||
| 75–79 | 0.46 (0.44–0.49) | 0.46 (0.44–0.49) | 0.46 (0.44–0.49) | 0.46 (0.44–0.49) | ||
| ≥80 | 0.20 (0.19–0.21) | 0.20 (0.19–0.21) | 0.20 (0.19–0.21) | 0.20 (0.19–0.21) | ||
| Language region | Swiss German | Reference | Reference | Reference | ||
| Romance | 0.89 (0.80–1.00) | 0.89 (0.80–0.99) | 0.89 (0.80–0.99) | |||
| Level of urbanization | Urban | Reference | Reference | Reference | ||
| Peri-urban | 1.19 (1.04–1.37) | 1.18 (1.02–1.35) | 1.14 (0.98–1.33) | |||
| Rural | 1.21 (0.99–1.47) | 1.19 (0.98–1.45) | 1.15 (0.93–1.43) | |||
| Mean SSEP (per 10 units) | 1.03 (0.89–1.19) | 1.02 (0.89–1.17) | 1.04 (0.91–1.20) | |||
| (Semi)private insurance status (per 10% change) | 1.03 (0.95–1.12) | 1.04 (0.96–1.13) | 1.02 (0.94–1.11) | |||
| Swiss citizenship (per 10% change) | 1.02 (0.94–1.10) | 1.02 (0.95–1.11) | 1.02 (0.95–1.11) | |||
| Burden of disease (per 1000 women)** | 1.08 (0.96–1.22) | 1.08 (0.96–1.22) | ||||
| Gynecologists (per 1/10,000 change)*** | 1.00 (0.98–1.01) | |||||
| Average time since graduation (per 5 years) | 1.05 (0.97–1.14) | |||||
| Remaining variance from the model (%)†† | 96.1 | 67.6 | 66.1 | 63.9 | ||
Abbreviations: CI = confidence interval; SSEP = Swiss neighborhood index of socioeconomic position. Results in bold indicate a statistically significant effect.
*Model 1: adjusted for the year of the procedure.
†Model 2: additional adjustment for age.
‡Model 3: additional adjustment for language region, socioeconomic factors (level of urbanization, SSEP, insurance status, and Swiss citizenship).
#Model 4: additional adjustment for burden of disease.
&Model 5: additional adjustment for the density of gynecologists and the average time since graduation.
§Hysterectomy rate in the defined category relative to the hysterectomy rate in the reference category. For instance, an incidence rate ratio of 0.95 indicates a 5% lower hysterectomy rate in Romance language regions than in Swiss German language regions.
**Sum of age-standardized incidence rates per 1000 women for hip fracture, colon or lung cancer treated surgically, acute myocardial infarction, and stroke. The IRR is the increase (or decrease in rates) when the burden of disease changes from e.g. 3 women with a comorbidity per 1000 to 4 women with a comorbidity per 1000 women.
***Density of gynecologists per 10,000 women. The IRR is the increase (or decrease) in rates when the density of gynecologists changes from e.g. 2 gynecologists per 10,000 persons to 3 per 10,000 women.
††Expresses the variance in hysterectomy rates from the average rate.