Results
A total of 1,910,661 women aged 15–49 were registered in Norway's National Population Register during the study period. Of these, 27,773 (1.5 %) were registered with endometriosis and 5432 (0.3 %) with adenomyosis in the specialist health service at least once. Both conditions were registered in 3029 women (0.2 %).
The rate of women registered with a diagnosis of endometriosis increased from 222 per 100,000 in 2008 to 513 per 100,000 in 2021, while the corresponding figure for adenomyosis increased from 25 to 72 per 100,000. Figure 1 shows the annual rate of women registered in the specialist health service with these conditions, with each woman counted only once per calendar year. Among women with at least one of the conditions, the median number of registered diagnoses was 2 (interquartile range: 1–5) over the entire study period. Between 2011 and 2021, the rate of presumed first-time registration increased from 85 to 152 per 100,000 for endometriosis and from 17 to 42 per 100,000 for adenomyosis (Figure 2).
The mean age at registration was 34 years (standard deviation: 7) for endometriosis and 37 years (standard deviation: 8) for adenomyosis. Figure 3 shows the rate for each age group for both conditions. Registrations of endometriosis peaked earlier than for adenomyosis, at 36 and 44 years, respectively. The rate of presumed first-time registration of the conditions (including only women with their first registration after 2011) was highest at age 32 for endometriosis (107 per 100,000) and 44 for adenomyosis (44 per 100,000) (Figure 4).
During the study period, a total of 194,813 women aged 15–49 were registered at least once with health problems related to endometriosis and adenomyosis (dysmenorrhea, dyspareunia and menorrhagia) in primary care. The corresponding figure in the specialist health service was 174,165. Table 1 shows the prevalence of the three symptoms among women with endometriosis or adenomyosis. The prevalence of all related health problems in both primary care and the specialist health service was higher among women with endometriosis or adenomyosis than among women with no registrations for these conditions (Table 1). For example, the proportion of women with dysmenorrhea registered in primary care was 21 % among those with endometriosis and 22 % among those with adenomyosis, compared with 4.5 % among women without these conditions registered in the specialist health service. Twelve per cent of women with endometriosis were registered with menorrhagia in primary care, compared with 19 % of those with adenomyosis and only 5 % of women without these conditions. Women registered with both endometriosis and adenomyosis had an even higher frequency of related health problems in primary care. Similar figures were observed for symptoms in the specialist health service.
Table 1
Number of women aged 15–49 registered in the specialist health service (records in the Norwegian Patient Registry (NPR)) with diagnoses of endometriosis and adenomyosis and main symptoms registered in primary care (records in the Norwegian Control and Payment of Health Reimbursements Database (KUHR)) in the period 1 January 2008 to 31 December 2021.
| Sector | Symptom | Endometriosis (n = 27 773) | Adenomyosis (n = 5 432) | Endometriosis and adenomyosis (n = 3 029) | Neither endometriosis nor adenomyosis (n = 1 880 485) |
|---|
| Primary care | Dysmenorrhea | 5 715 (20.6) | 1 202 (22.1) | 784 (25.9) | 83 686 (4.5) |
| | Dyspareunia | 1 277 (4.6) | 254 (4.7) | 157 (5.2) | 2 461 (0.1) |
| | Menorrhagia | 3 387 (12.2) | 1 048 (19.3) | 484 (16.0) | 90 918 (4.8) |
| Specialist health service | Dysmenorrhea | 7 062 (25.4) | 1 785 (32.9) | 1 271 (42.0) | 34 080 (1.8) |
| | Dyspareunia | 2 377 (8.6) | 560 (10.3) | 372 (12.3) | 29 226 (1.6) |
| | Menorrhagia | 5 362 (19.3) | 2 045 (37.6) | 1 030 (34.0) | 112 739 (6.0) |