Table 5. Factors associated with renal function testing behaviour less frequent than recommended by guidelines, among current PrEP users, Germany, 2018 and 2019 (n = 3,618).
| Adequate renal test frequency n = 2,561 |
Inadequate renal test frequency n = 1,057 |
Univariable analysisa | Multivariable analysisb | |||||
|---|---|---|---|---|---|---|---|---|
| OR (95% CI) | p valuec | aOR (95% CI) | p valuec | |||||
| Source of current PrEP | ||||||||
| Medical prescription | 2,316 | 90.4 | 714 | 67.5 | 1 | 1 | ||
| Informal | 235 | 9.2 | 340 | 32.2 | 4.7 (3.9–5.7) | < 0.001 | 2.9 (2.3–3.7) | < 0.001 |
| Missing | 10 | 0.4 | 3 | 0.3 | Not included | |||
| Type of current PrEP use | ||||||||
| Daily | 2,103 | 82.1 | 458 | 43.3 | 1 | 1 | ||
| On demand/intermittent | 452 | 17.6 | 597 | 56.5 | 6.1 (5.2–7.1) | < 0.001 | 4.9 (4.1–5.9) | < 0.001 |
| Missing | 6 | 0.2 | 2 | 0.2 | Not included | |||
| Age (years) | ||||||||
| 18–29 | 475 | 18.5 | 266 | 25.2 | 1.4 (1.2–1.7) | < 0.001 | 1.4 (1.1–1.7) | 0.011 |
| 30–39 | 946 | 36.9 | 374 | 35.4 | 1 | 1 | ||
| 40–49 | 767 | 29.9 | 260 | 24.6 | 0.9 (0.7–1.0) | 0.103 | 0.8 (0.6–1.0) | 0.043 |
| 50–80 | 359 | 14.0 | 142 | 13.4 | 1.0 (0.8–1.3) | 0.997 | 0.9 (0.7–1.2) | 0.403 |
| Missing | 14 | 0.5 | 15 | 1.4 | Not included | |||
| Country of origin | ||||||||
| Germany | 1,774 | 69.3 | 627 | 59.3 | 1 | 1 | ||
| Outside Germany | 487 | 19.0 | 266 | 25.2 | 1.5 (1.3–1.8) | < 0.001 | 1.3 (1.1–1.6) | 0.006 |
| Missing | 300 | 11.7 | 164 | 15.5 | Not included | |||
| Annual gross income (EUR) | ||||||||
| < 30,000 | 633 | 24.7 | 302 | 28.6 | 1.2 (1.0–1.5) | 0.025 | 1.0 (0.8–1.2) | 0.790 |
| 30,000–49,000 | 760 | 29.7 | 291 | 27.5 | 1 | 1 | ||
| ≥ 50,000 | 997 | 38.9 | 378 | 35.8 | 1.0 (0.8–1.2) | 0.914 | 1.0 (0.8–1.2) | 0.774 |
| Missing | 171 | 6.7 | 86 | 8.1 | Not included | |||
| Gender | ||||||||
| Cisgender male | 2,516 | 98.2 | 1,025 | 97.0 | 1 | 1 | ||
| Gender-diverse | 29 | 1.1 | 17 | 1.6 | 1.4 (0.8–2.6) | 0.237 | 0.9 (0.4–2.0) | 0.845 |
| Missing | 16 | 0.6 | 15 | 1.4 | Not included | |||
| Test before starting PrEP | ||||||||
| Yes | 2,545 | 99.4 | 914 | 86.5 | 1 | d | ||
| No | 14 | 0.5 | 127 | 12.0 | 25.3 (14.5–44.1) | < 0.001 | ||
| Missing | 2 | 0.1 | 16 | 1.5 | Not included | |||
| Payment for testing | ||||||||
| Cost coveragee | 1,430 | 55.8 | 351 | 33.2 | 1 | d | ||
| Self-payment | 1,028 | 40.1 | 272 | 25.7 | 1.1 (0.9–1.3) | 0.407 | ||
| Missing | 103 | 4.0 | 434 | 41.1 | Not included | |||
| Location of testing, | ||||||||
| Physician | 2,002 | 78.2 | 413 | 39.1 | 1 | d | ||
| Physician and other locations | 282 | 11.0 | 86 | 8.1 | 1.5 (1.1–1.9) | 0.004 | ||
| Only using checkpoints, self-tests, or other locations | 267 | 10.4 | 161 | 15.2 | 2.9 (2.3–3.7) | < 0.001 | ||
| Missing | 10 | 0.4 | 397 | 37.6 | Not included | |||
| Number of anal/vaginal sex partners within the last 6 months | ||||||||
| 0–3 | 302 | 11.8 | 204 | 19.3 | 2.2 (1.8–2.7) | < 0.001 | d | |
| 4–10 | 796 | 31.1 | 399 | 37.7 | 1.6 (1.4–1.9) | < 0.001 | ||
| > 10 | 1,412 | 55.1 | 430 | 40.7 | 1 | |||
| Missing | 51 | 2.0 | 24 | 2.3 | Not included | |||
| Condom use while taking PrEP | ||||||||
| Always/often | 485 | 18.9 | 265 | 25.1 | 1.4 (1.2–1.7) | < 0.001 | d | |
| About half of the times/sometimes/never |
2,049 | 80.0 | 779 | 73.7 | 1 | |||
| Missing | 27 | 1.1 | 13 | 1.2 | Not included | |||
CI: confidence interval; OR: odds ratio; PrEP: pre-exposure prophylaxis; STI: sexually transmitted infection.
a Univariable logistic regression model.
b Multivariable logistic regression model to investigate the association of informal PrEP use and infrequent testing behaviour including 2,155 participants with adequate and 858 participants with inadequate renal testing frequency, adjusting for age, gender, country of origin, annual gross income and type of PrEP use.
c Wald test.
d Not included in the multivariable regression model (see Supplement, section S1 for selection of confounders).
e For some PrEP users, the costs for tests can be covered by health insurance in case of symptomatic infection or HIV/STI diagnoses among sexual partners or through clinical trials.