Descriptive analysis
Table 2 summarizes the proportion of women in each anemia group, when the groups were classified using the explanatory variables and the chi-square test. The chi-square test indicated that the differences observed in the percentage of women classified as anemic based on factors such as SES, respondent education level, place of residence, age, maternity status, fasting blood plasma glucose level and nutritional status, were statically significant (p < 0.05). The concentration index indicates that the trends of anemia, underweight, prediabetes and diabetes were stronger in the individuals belonging to low SES category (Table 3).
Table 2
Percentages of women with anemia by standard of explanatory variables ( N = 5886)
| | *Anemia status by hemoglobin level % | | |
Variable | n (%) | Not anemic | Mild | Moderate/ Sever | Chi-square result | P value |
Socioeconomic status | | | | | | |
Low | 4,265 (72.46) | 54.59 | 37.50 | 7.90 | 92.63 | < .01 |
Medium | 434 (7.37) | 59.38 | 37.05 | 3.57 | | |
High | 1,187 (20.17) | 70.94 | 24.00 | 5.06 | | |
Socio-demographic factors | | | | | | |
Highest Education level | | | | | | |
No education | 2,605(44.26) | 54.46 | 37.00 | 8.54 | 46.88 | < .01 |
Completed primary | 2,553 (43.37) | 59.78 | 34.23 | 5.98 | | |
Completed secondary or higher | 728 (12.37) | 67.57 | 27.67 | 4.76 | | |
Place of residence | | | | | | |
Rural | 3,863 (65,63) | 55.92 | 36.81 | 7.27 | 26.11 | < .01 |
Urban | 2,023 (34.37) | 62.91 | 30.50 | 6.52 | | |
Employment status | | | | | | |
Employed | 853 (85.49) | 58.35 | 34.62 | 7.04 | 0.50 | .80 |
Not employed | 5,027 (14.51) | 57.33 | 35.68 | 6.99 | | |
Sex of house old head | | | | | | |
Male | 5,301(90.06) | 57.95 | 34.86 | 7.18 | 1.93 | .38 |
Female | 585 (9.94) | 61.12 | 33.52 | 5.36 | | |
Number of child | | | | | | |
No child | 2903 (39.10 | 58.09 | 35.01 | 6.90 | 2.49 | .87 |
One | 2,145 (36.44) | 57.61 | 35.01 | 7.39 | | |
Two | 670 (11.38) | 60.87 | 32.34 | 6.80 | | |
Three or more | 168 (2.85) | 58.20 | 36.38 | 5.42 | | |
Age | | | | | | |
Early reproductive | 889 (15.10) | 57.13 | 35.18 | 7.69 | 16.13 | .04 |
Middle reproductive | 3,502 (59.50) | 58.68 | 34.65 | 6.67 | | |
Late reproductive | 637 (10.82) | 62.70 | 31.21 | 6.09 | | |
Early premenopause | 488 (8.29) | 52.78 | 34.21 | 9.01 | | |
Late premenopause | 370 (6.29) | 56.01 | 36.20 | 7.79 | | |
Family size | | | | | | |
Small | 4,835 (82.14) | 57.93 | 34.77 | 7.30 | 3.24 | .19 |
Large | 1,051 (17.86) | 69.60 | 34.62 | 5.78 | | |
Maternity status | | | | | | |
Pregnant | 372 (6.32) | 47.92 | 38.20 | 13.88 | 83.17 | .01 |
Lactating | 1356 (23.06) | 58.10 | 34.11 | 7.79 | | |
Neither | 4158 (70.06) | 61.61 | 32.29 | 6.10 | | |
Diabetes | | | | | | |
Normal | 5076 (86.25) | 59.67 | 33.59 | 6.74 | 1.26 | .04 |
Prediabetic | 523 (8.87) | 60.89 | 35.10 | 4.01 | | |
Diabetic | 287 (4.86) | 59.95 | 32.70 | 7.36 | | |
BMI** | | | | | | |
Underweight (< 18.50) | 1,395 (23.86) | 49.58 | 42.26 | 8.15 | 94.68 | < .01 |
Normal (18.50, 24.99) | 3,422 (58.20) | 58.44 | 34.22 | 7.35 | | |
Overweight (25,30) | 886 (14.81) | 68.91 | 26.22 | 4.87 | | |
Obese (> 30) | 183 (3.13) | 72.70 | 34.67 | 2.63 | | |
**Weight gain rate of weight gain during pregnancy(Institute of Medicine 2009), that also adopt by BDHS (National Institute of Population Research and Training 2013a) |
Table 3
Summary measures of SES inequality and the prevalence of anemia, underweight, diabetes and prediabetes among ever-married women aged 15 to 49 years
Variable | Concentration indexc | Standard error (SE) | P-value |
Underweight women | − .52 | .03 | < .001 |
Anemic women | − .42 | .01 | .002 |
Pre-diabetic women | − .32 | .01 | .04 |
Diabetic women | − .30 | .04 | .02 |
C Obtained by the formula 2σ2 r (hi/µ)=α + βri +εi;, h is the health variable whose inequality is being measured, µ is its mean, ri is the ith individual’s fractional rank (for example if a women is underweight and which SES group she is belonging) in the socioeconomic distribution, σ2 r is the variance of the fractional rank, The estimate β is equal to the concentration index, ri= underweight women, anemic women, pre-diabetic women, diabetic women α is constant (underweight women = .65, anemic women = .95, pre-diabetic women = .94, diabetic women = .84) and εi is the error term. Concentration index has a negative value when the health indicator is concentrated among the disadvantaged; A positive value when the health indicator is concentrated among the advantaged; When there is no inequality the value is equals 0; the theoretical maximum is ± 1. |
Effect of household economic inequality and other confounders
The results of the ordered logit models are presented in Table 4. The women from low and medium SES groups showed the higher odds (OR, 1.90, 95% CI, 1.65–2.17; p < .01 and OR, 1.41, 95% CI, 1.12–1.78; p < .01) of being anemic when compared to the high SES group in an unadjusted model (Model 1). From Model 2, it is evident that women with no education or primary educational attainment were more likely to be anemic in comparison to those who had completed secondary or higher education (OR, 1.22, 95% CI, 1.05–1.42 & OR, 1.15 95% CI, 1.01–1.3; p < 0.01 respectively).
Table 4
The determinants of anemia in women in Bangladesh (obtained from ordinal logistic regression models) (N = 5886)
| Model 1 | | Model 2 | | Model 3 | | Model 4 | |
| Odds ratio (95% CI) | P Value | Odds ratio ( 95% CI) | P Value | Odds ratio ( 95% CI) | P Value | Odds ratio ( 95% CI) | P Value |
Socioeconomic status | | | | | | | | |
Low | 1.90 (1.65,2.17) | < 0.01 | 1.69 (1.43,1.99) | < 0.01 | 1.36 (0.85,2.15) | 0.20 | 1.23 (0.69, 1.83) | 0.62 |
Medium | 1.41(1.12,1.78) | < 0.01 | 1.35 (1.07,1.70) | < 0.01 | 1.15 (0.6,2.19) | 0.66 | 1.11 (0.58, 2.11) | 0.76 |
High | 1 | | 1 | | 1 | | 1 | |
Socio-demographic factors | | | | | | | | |
Education | | | | | | | | |
No education | | | 1.22 (1.05,1.42) | < 0.01 | 1.21(0.79,1.84) | 0.37 | 1.17 (.76, .80) | 0..46 |
Completed primary | | | 1.15 (1.01, 1.31) | 0.03 | 1.25 (0.82,1.91) | 0.30 | 1.29 (.8,1.88) | 0.35 |
Completed secondary or higher | | | 1 | | 1 | | | |
Place of residence | | | | | | | | |
Rural | | | 1.07 (0.94,1.22) | 0.30 | 1.06 (0.72,1.54) | 0.78 | .99 (67,1.46) | 0.96 |
Urban | | | 1 | | 1 | | 1 | |
Currently working | | | | | | | | |
Yes | | | 1.05 (.90,1.23) | 0.49 | 1.08 (0.68,1.53) | 0.94 | 0.99 (.67,1.46) | 0.98 |
No | | | 1 | | | | 1 | |
Sex of house old head | | | | | | | | |
Female | | | .93 (0.78,1.12) | 0.45 | .79 (0.50,1.27) | 0.34 | .82 (0.65,1.50) | 0.41 |
Male | | | 1 | | 1 | | 1 | |
Number of child | | | | | | | | |
No child | | | 1 | | 1 | | 1 | |
One | | | 0.99 (0.89,1.12 | 0.96 | 0.96 (0.69,1.33) | 0.81 | 0.95 (0.69,1.32) | 0.77 |
Two | | | 0.90 (0.75,1.07) | 0.24 | 1.21 (0.73,2.01) | 0.45 | 1.23 (0.74,2.06) | 0.42 |
Three or more | | | 1.01 (0.73,1.40) | 0.94 | 1.08 (0.39,2.97) | 0.88 | 1.06 (0.38,2.92) | 0.91 |
Age | | | | | | | | |
Early reproductive | | | 1 | | 1 | | 1 | |
Middle reproductive | | | 0.92 (0.78,1.07) | 0.26 | 0.77 (0.49,1.22) | 0.27 | .83 (0.52,1.32) | 0.44 |
Late reproductive | | | 0.79 (0.64,0.99) | 0.04 | 0.59**(0.37,0.93) | 0.02 | .62 (0.39,0.98) | 0.04 |
Early premenopause | | | 1.12 (0.88,1.42) | 0.35 | 0.89 (0.55,1.44) | 0.63 | .94 (0.58,1.53) | 0.81 |
Late premenopause | | | 1.10 (0.86,1.43) | 0.43 | 0.76 (0.82,1.48) | 0.53 | .71 (0.73, 1.36) | 0.17 |
Family size | | | | | | | | |
Small | | | 1 | | 1 | 1 | 1 | |
Large | | | 1.01(0.87,1.16) | 0.91 | 1.05 (0.69,1.59) | 1.05 | 1.06 (.70,1.61) | 0.79 |
Diabetics and Maternity status | | | | | | | | |
Maternity status | | | | | | | | |
Pregnant | | | | | 1.74 (1.12, 4.20) | < 0.01 | 1.7 (1.12,4.02) | 0.03 |
Lactating | | | | | 1.62 (1.09,3.70) | 0.03 | 1.47(0 .11,3.99) | 0.14 |
Neither | | | | | 1 | | 1 | |
Fasting plasma glucose levels | | | | | | | | |
Normal | | | | | 1 | | 1 | |
Prediabetic | | | | | .67 (0.39,1.15) | 0.15 | .68 (0.39, 1.70) | 0.17 |
Diabetic | | | | | 1.67(0.78,3.49) | 0.18 | 1.74 (1.02, 3.68) | 0.04 |
Nutritional status | | | | | | | | |
BMIb | | | | | | | | |
Underweight (< 18.50) | | | | | | | 1.34 (.92,1.96) | 0.13 |
Normal (18.50, 24.99) | | | | | | | 1 | |
Overweight (25,30) | | | | | | | .62 (.39,0.97) | 0.04 |
Obese (> 30) | | | | | | | .66 (.30,1.45) | 0.30 |
The likelihood of being anemic appear as slightly truncated for low and medium SES groups (model 2) in comparison to the high SES group when sociodemographic variables were added to the bivariate analysis (Model 1) (OR, 1.9, 95% CI, 1.65–2.17 to OR, 1.69, 95% CI, 1.43–1.99 and OR, 1.41, 95% CI, 1.21–1.78 to OR,1.35, 95% CI,1.07–1.7; p < 0.01 respectively) .
After adding the variables for maternity and diabetes the likelihood of having anemia in the subjects from low and medium SES households vs. high SES households, and individuals having primary and secondary or higher secondary education vs. their counterpart with no educational attainment became insignificant (p > 0.05). The maternity status was also found to be a significant factor contributing to anemia in Model 4. The pregnant women were observed to be approximately two times more prone to being mild anemic (OR, 1.70, 95% CI, 1.12–4.02; p < .05) while lactating women appeared to be insignificant ( OR, 1.47, 95% CI, 0.11–3.99; p > 0.05) anemic as compared to women who were neither pregnant nor lactating. Diabetes mellitus was found as an associate factor of anemia in the full model (Model 4). Women who were suffering from diabetes mellitus were observed to have 74% higher chance of being 1.74 times, (OR, 1.74, 95% CI 1.02–3.86; p < 0.05) for being mildly, moderately or severely anemic as compared to the subjects with normal blood plasma glucose levels. The overweight women with BMI in the range of 25–30 kg/m2 were observed to be approximately two times less likely to be anemic than those with a normal BMI (OR, 0.62, 95% CI, 0.39–0.97; p < .05). Similarly, the women belonging to the early reproductive (< 20 years) age group were observed to be around 38% times less likely to be anemic than those who belonged to the late reproductive age group (OR, .62, 95% CI, .39-.98; p < .05) (Model 4).
It was evident from Models 3 and 4 that after controlling the variable for nutritional status (BMI), the strength of the associations between anemia and pregnancy status became low(OR, 1.74, 95% CI, 1.12 − 4.20; p < 0.01 to OR, 1.7, 95% CI, 1.12 − 4.20; p < 0.05 vs. subject neither pregnant or lactating)