Social inequalities in the use of contraceptives in adult women from Southern Brazil

ABSTRACT OBJECTIVE: To describe the contraceptive methods used by adult women and the associated socioeconomic and demographic factors. METHODS: Population-based cross-sectional study with 20 to 49-year-old women from São Leopoldo, state of Rio Grande do Sul, in 2015. Three outcomes were considered to analyze the association with demographic and socioeconomic characteristics: use of oral contraceptive pills, tubal ligation and male condom. The crude prevalence ratios, stratified by age, and 95% confidence intervals (95%CI) were obtained using Poisson regression, taking the experimental error into account. RESULTS: A total of 736 women, aged from 20 to 49 years old, were evaluated. The prevalence of the use of oral contraceptive pills, tubal ligation and male condom were respectively 31.8% (95%CI 28.4–35.3), 11.1% (95%CI 9.0–13.6) and 10.9% (95%CI 8.7–13.3). In addition, 10.5% (n = 77) of the women reported making combined use of oral contraceptive pills and condom. In the stratified analysis, younger women with lower education level and from lower social classes reported less use of oral contraceptive pills. Tubal ligation was more prevalent among the lower social classes, but only in the age group from 30 to 39 years old. No differences were found in relation to male condom. CONCLUSIONS: The results indicated that differences persist in relation to contraception, which can be associated with both the difficulties of access to these inputs and the frailty of actions in reproductive health to achieve the needs and preferences of women who are more socially vulnerable.

摘要：
**目的**：描述成年女性所采用的避孕方式及其相关社会经济与人口学因素。
**方法**：本研究为基于人群的横断面研究，研究对象为2015年来自巴西南里奥格兰德州圣莱奥波尔迪市的20~49岁女性。本研究选取3个结局指标以分析其与人口学及社会经济特征的关联：口服避孕药(oral contraceptive pills)、输卵管结扎术(tubal ligation)与男用避孕套(male condom)。采用考虑实验误差的泊松回归(Poisson regression)计算按年龄分层的粗患病率比及95%置信区间(95% confidence intervals, 95%CI)。
**结果**：本研究共纳入736名20~49岁女性进行评估。口服避孕药、输卵管结扎术及男用避孕套的使用率分别为31.8%（95%CI 28.4~35.3）、11.1%（95%CI 9.0~13.6）及10.9%（95%CI 8.7~13.3）。此外，10.5%（n=77）的女性报告同时联合使用口服避孕药与避孕套。分层分析显示，受教育程度较低、社会阶层较低的年轻女性口服避孕药使用率更低。输卵管结扎术在社会阶层较低人群中更为普遍，但该差异仅见于30~39岁年龄组。男用避孕套使用率未发现相关差异。
**结论**：研究结果表明，避孕方式使用仍存在社会经济层面的差异，这可能与避孕用品获取难度较高，以及生殖健康服务未能充分满足社会弱势女性的健康需求与个人偏好有关。