Food Insecurity, Prenatal Care and Other Anemia Determinants in Pregnant Women from the NISAMI Cohort, Brazil: Hierarchical Model Concept

Abstract Objective To identify the prevalence of anemia and its relation to food insecurity (FI) and other determinants in pregnant women. Methods A cross-sectional, cohort-nested study, with the participation of 245 pregnant women who were cared for at Family Health Units in the municipality of Santo Antônio de Jesus, Bahia, Brazil. The participants underwent blood tests for hemoglobin levels, anthropometric examinations, and answered a structured questionnaire. The hemoglobin (Hb) parameter (Hb < 11 g/dL) was used for the classification of the diagnosis of anemia. Food insecurity was evaluated using the North American short-scale food insecurity assessment. Logistic regression was adopted for the statistical analyses, based on a hierarchical conceptual model that enabled the measurement of the decomposition of the total effect of its non-mediated and mediated components using the proposed hierarchical levels. Results The prevalence of anemia in the studied population was of 21.8%, and the average hemoglobin was 12.06 g/dL (standard deviation [SD]: 1.27). Food insecurity was identified in 28.16% of the pregnant women. The average maternal age was 25.82 years (SD: 5.94). After ranking, the variables positively associated with anemia remained significant: FI (odds ratio [OR] =3.63; 95% confidence interval [95%CI]: 1.77-7.45); not undergoing prenatal care (OR = 5.15;95%CI: 1.43-18.50); multiparity (OR = 2.27;95%CI: 1.02-5.05); and non-supplementation of iron medication (OR = 2.45; 95%CI: 1.04-5.76). The results also indicated that the socioeconomic and environmental factors were largely mediated by food insecurity and factors regarding prenatal care. Conclusions In the present study, the chance of occurrence of anemia in pregnant women was significantly higher,mainly among women: in situations of food insecurity, not undergoing prenatal care, not having received iron supplements, and who are multiparous.

摘要
研究目的：明确孕妇贫血的患病率，及其与粮食不安全（Food Insecurity，FI）及其他影响因素的关联。
研究方法：本研究为横断面嵌套队列研究，纳入巴西巴伊亚州圣安东尼奥-迪热苏斯市家庭卫生单元接诊的245名孕妇作为研究对象。所有参与者均接受血红蛋白（Hemoglobin，Hb）水平检测、人体测量学检查，并填写结构化调查问卷。本研究以Hb<11 g/dL作为贫血的诊断分类标准；采用北美简短版粮食不安全评估量表对粮食不安全状况进行评估；统计分析采用基于层级化概念模型的logistic回归分析，该模型可通过预设层级分解总效应中的非介导与介导组分。
研究结果：本研究人群的贫血患病率为21.8%，平均血红蛋白水平为12.06 g/dL（标准差（Standard Deviation，SD）：1.27）。28.16%的孕妇存在粮食不安全状况，研究对象的平均产妇年龄为25.82岁（SD：5.94）。经分层分析后，与贫血呈正相关且仍具有统计学显著性的变量包括：粮食不安全（比值比（Odds Ratio，OR）=3.63；95%置信区间（Confidence Interval，95%CI）：1.77~7.45）、未接受产前保健（OR=5.15；95%CI：1.43~18.50）、经产妇（OR=2.27；95%CI：1.02~5.05）以及未补充铁剂（OR=2.45；95%CI：1.04~5.76）。研究结果同时表明，社会经济与环境因素主要通过粮食不安全及产前保健相关因素发挥介导作用。
研究结论：本研究显示，孕妇发生贫血的风险显著升高，尤其多见于以下人群：存在粮食不安全状况者、未接受产前保健者、未补充铁剂者以及经产妇。