Background information
In this study, a total of 7740(weighted) non first birth children in the 5 years prior to the survey were included in the analysis. Among the total women (mothers of children) whose data were analyzed 45 % (3483) of them were with the age range of 20-29 years, nearly three-fourth 74 % (5728) of them were uneducated and 25 % (1935) were from poorest households. The majority 91% (7043) of the respondents resides in rural areas and 44.7% (3460) of the respondents were from Oromiya region and also 30% (2322) of women were use modern contraception method. The median birth interval of the study population was 32 months; thus, half of non-first births occur within 3 years after the first birth. One in four births (25%) occurs within less than 2 years after the previous birth.
Table 1 Individual Level Factors of women participated on EDHS (2016), Ethiopia. (N=7740)
Background characteristics
|
Birth Interval
|
Total (%)
|
Number of non-first birth
|
Median birth interval
|
|
Short (%) Normal (%)
|
|
Individual level factors
|
|
Sex
Male
Female
|
25(1004)
25.3(942)
|
75(3013)
74.7(2781)
|
100.00
100.00
|
4017
3723
|
31.8
32.1
|
|
Age
|
46(20)
28(979)
22.1(762)
21.9(165)
|
54(23)
72(2516)
78.1(2688)
78.1(587)
|
100.00
100.00
100.00
100.00
|
43
3495
3450
752
|
24.5
30.6
32
33.5
|
|
Occupation
Working
Not working
|
23.4(780)
26.4(1163)
|
76.6(2554)
27.6(3243)
|
100.00
100.00
|
3334
4406
|
33
26.8
|
|
Education
No education
|
Primary
|
Secondary
|
Higher
|
|
25.9(1497)
23(389)
16.7(32)
25(19)
|
74.1(4282)
77(1303)
83.3(160)
75(57)
|
100.00
100.00
100.00
100.00
|
5779
1693
192
76
|
31.6
33
38.4
29.7
|
|
Wealth quintile
Poorest
|
Poorer
|
Middle
|
Richer
|
Richest
|
|
29.2(611)
27.1(508)
23.6(381)
21.7(295)
18.1(145)
|
71.8(1482)
72.9(1365)
76.4(1234)
78.3(1065)
81.9(654)
|
100.00
100.00
100.00
100.00
100.00
|
2093
1873
1615
1360
799
|
31
30.9
31.9
32
35.3
|
|
Status of prior birth
Living
|
Dead
|
|
24.1(1760)
41(179)
|
75.9(5543)
59(258)
|
100.00
100.00
|
7303
437
|
32.4
26.2
|
|
|
23(640)
26.4(831)
25.9(469)
|
77(2142)
73.6(2316)
74.1(1342)
|
100.00
100.00
100.00
|
2782
3147
1811
|
32.7
31.5
31.5
|
|
Contraceptive use
Modern
Traditional
Non-user
|
22.2(469)
42.8(9)
26.1(1463)
|
77.8(1644)
57.2(12)
73.9(4143)
|
100.00
100.00
100.00
|
2113
21
5606
|
33.8
28.3
31.3
|
|
Breastfeeding habit
Never
Not currently
Still breast feed
|
32(124)
29.2(1230)
18.7(588)
|
68(263)
70.8(2981)
81.3(2554)
|
100.00
100.00
100.00
|
387
4211
3142
|
30.3
30
34.3
|
|
Total
|
25%(1935)
|
75%(5805)
|
100.00
|
7740
|
32
|
|
Table2 Community Level Factors of Women participated on EDHS (2016), Ethiopia. (N=7740)
Background characteristics
|
Birth Interval
|
Total
|
Number of non-first birth
|
Median birth interval
|
Community level factors
|
Short (%) Normal (%)
|
|
23(123)
25(1801)
|
77(413)
75(5403)
|
100.00
100.00
|
536
7204
|
34.1
31.9
|
Region
Tigray
|
Affar
|
Amhara
|
Oromiya
|
Somali
|
Ben-Gumz
|
SNNP
|
Gambela
|
Harari
|
Addis Abeba
|
Dire Dawa
|
|
14.5(64)
36.5(30)
14.6(179)
27.5(1005)
47.6(203)
27.7(25)
24.3(409)
17.6(3)
29.5(5)
19.5(17)
34.5(10)
|
83.5(376)
63.5(52)
83.4(1047)
72.5(2649)
52.4(223)
72.3(65)
75.8(1274)
82.4(13)
71.5(12)
81.5(70)
65.5(19)
|
100.00
100.00
100.00
100.00
100.00
100.00
100.00
100.00
100.00
100.00
100.00
|
440
82
1226
3654
426
90
1683
16
17
87
29
|
36.7
25.4
37.3
30.3
24.7
30.9
31.9
34.8
29.3
35.8
30.9
|
Community poverty
Low
High
|
20.2(571)
27.8(1366)
|
79.8(2257)
73.2(3546)
|
100.00
100.00
|
2828
4912
|
34.1
30.5
|
Community education
Low
High
|
26.5(1376)
22.3(568)
|
73.5(3815)
77.3(1981)
|
100.00
100.00
|
5191
2549
|
31.1
33.6
|
Total
|
25%(1935)
|
75%(5805)
|
100.00
|
7740
|
32
|
Spatial distribution of short birth interval
Spatial auto correlation
This study identified that the spatial distribution of birth interval was found non-random distribution with Moran’s I 0.065 z-score 2.17 and p-value 0.029.
Based on EDHS-2016 sampled data, geostatistical(local gets ord) analysis predict that highest percent of short birth intervals were detected in North-Eastern of Somali regional zones, some southern part of Affar regional zones, Eastern part of Oromiya regional zones, some part of Harari regional zones and Dire Dawa.
Cluster outlier’s areas were detected by using local Moran’s I (Anselin). Higher cluster outlier areas were found in Addis Abeba, western zone of Tigray, Harari, some parts of Benishagul and SNNPR. On the other hand low cluster outliers were detected in some western parts of Benishagul and some Eastern parts of Gambela regional states.
Spatial interpolation
Based on EDHS 2016 sampled data geostatistical analysis predict that highest short birth interval percentage were detected mainly in Somali , Affar, Oromiya and Amhara regions.
Multilevel logistic regression analysis
The results of the empty model (Model 1) explained that there was a statistically significant variability in the odds of birth intervals between communities. Similarly, the ICC in the empty model implied that 16.4 % of the total variance in the distribution of birth interval was attributed to differences between communities.
In model II only individual variables which examines duration of birth interval with individual factors with p- value less than 0.2 were added. The results showed that women age, index child living status, household wealth index, occupation, birth order and breastfeeding habit were significantly associated with duration of birth interval. The ICC in Model II indicated that, 11.2 % of the variation in women’s birth interval distribution was attributable to differences across communities. As shown by the PCV, 26% of the variance in distribution of birth interval across communities was explained by the individual level characteristics.
In Model III only community level variables with p-value less than 0.2 were added. The result showed that women from urban areas, residing in communities with low poverty level, residing in communities with low education level and region were significantly associated birth interval. The ICC in Model III implied that differences between communities account for about 8.3 % of the variation in women’s preceding birth interval. In addition, the PCV indicated that 41.2 % of the variation in preceding birth interval between communities was explained by community level characteristics.
The final model was Model IV which included both individual and communities factor. Additionally model IV was used for the interpretation of this study findings because of its model fitness than the reset three models. By holding other individual and communities factors constant, women aged 20-29 were 57% less likely to have subsequent birth compared to those age group 15-19 years (AOR 0.43 CI 0.22-0.84). Likewise women aged 30-39 years were 70% (AOR 0.30 CI 0.15-0.59) and women aged 40-49 years were 70% (AOR 0.30 CI 0.15-0.61) less likely to have subsequent birth respectively.
After controlling other factors constant women from richest households were 54% [AOR 0.46 95% CI 0.33-0.63]; women from richer households were 20 % [AOR 0.80 95% CI 0.65-0.98] and women from middle economic households were 20 % [AOR 0.80 95% CI 0.66-0.97] less likely to have a subsequent birth as compared to women from poorest households.
Women whose index child died were 78% more likely to have subsequent birth compared with women whose index child is alive [AOR 1.78, 95% CI 1.41-2.24]. Women who breastfed until the survey time were 39% less likely to have subsequent birth compared to those who never breastfed their child [AOR 1.84, 95% CI1.41-2.39].
With respect to region, women from Tigray and Amhara regional state were among the ones who had reported the highest number of women with normal birth intervals. They were nearly 79% less likely to have subsequent birth [AOR 0.21, 95% CI 0.14-0.33] [AOR 0.21, 95% CI 0.14-0.30]. Respectively than women in Somali regional state which had the highest number of women with subsequent birth, Women reside in Gambela 77%, in SNNPR 62%, in Oromiya 60% and in Addis Abeba 57% less likely to have subsequent births than Somali regional state [AOR 0.23, 95% CI 0.06-0.93] [AOR 0.38, 95% CI 0.27-0.53] [AOR 0.40, 95% CI 0.29-0.55 ] [AOR 0.43, 95%CI 0.21-0.89] respectively.
Table 3 Multilevel Analysis for Individual Level Factors (EDHS 2016), Ethiopia
Characteristics fixed effects
|
Model I
|
Model II
AOR (CI 95%)
|
Model III
AOR (CI 95%)
|
Model IV
AOR (CI 95%)
|
Sex
Male
Female
|
|
0.96(0.86-1.10)
1
|
-
-
|
0.96(0.85-1.07)
1
|
Age
|
|
1
0.32(0.16-0.62)
0.17(0.08-0.33)
0.15(0.07-0.30)
|
-
-
- -
|
1
0.43(0.22-0.84)**
030(0.15-0.59)***
0.30(0.15-0.61)***
|
Education
No education
|
Primary
|
Secondary
|
Higher
|
|
|
1
1.06(.91-1.23)
1.18(.76-1.86)
1.59(.85-2.99)
|
-
-
-
-
|
1
0.90(0.77-1.05)
0.92(0.58-1.44)
1.02(0.54-1.92)
|
Wealth quintile
Poorest
|
Poorer
|
Middle
|
Richer
|
Richest
|
|
|
1
0.86(0.72-1.01)
0.67(0.56-0.81)
0.66(0.54-0.80)
0.47(0.36-0.61)
|
-
-
-
-
-
|
1
0.96(0.81-1.14)
0.80(0.66-0.97)**
0.80(0.65-0.98)**
0.46(0.33-0.63)***
|
Status of prior birth
Living
|
Dead
|
|
|
1
1.66(1.32-2.09)
|
-
-
|
1
1.78(1.41-2.24)***
|
|
|
1
1.11(0.97-1.26)
1.04(0.89-1.21)
|
-
-
-
|
1
1.23(0.98-1.35)
1.13(0.97-1.31)
|
Contraceptive use
Modern
Traditional
Non-user
|
|
1.05(0.92-1.22)
3.75(0.71-9.80)
1
|
-
-
-
|
1.13(0.98-1.30)
3.65(0.89-9.45)
1
|
Breastfeeding habit
Never
Not currently
Still breast feed
|
|
1
0.93(0.72-1.20)
0.53(0.40-0.70)
|
-
-
-
|
1
0.98(0.76-1.27)
0.61(0.46-0.80)***
|
Occupation
Working
Not working
|
|
0.87(0.77-0.98)
1
|
-
-
|
0.98(0.86-1.11)
1
|
Characteristic fixed effect
|
Model I
|
Model II
|
Model III
|
Model IV
|
|
|
-
-
|
-
-
|
1.08(.72-1.44)
1
|
.77(.53-1.14)
1
|
|
Region
Tigray
|
Affar
|
Amhara
|
Oromiya
|
Somali (R)
|
Ben-Gumz
|
SNNP
|
Gambela
|
Harari
|
Addis Abeba
|
Dire Dawa
|
|
-
-
-
-
-
-
-
-
-
-
-
|
-
-
-
-
-
-
-
-
-
-
-
|
0.18(.12-.28)
0.63(0.35-1.10)
0.19(0.14-0.27)
0.37(0.27-0.50)
1
0.43(0.24-0.76)
0.34(0.25-0.48)
0.24(0.06-0.92)
0.55(0.18-1.72)
0.36(0.18-0.72)
0.61(0.25-0.15)
|
0.21(0.14-0.33)***
0.59(0.33-1.04)
0.21(0.14-0.30)***
0.40(0.29-0.55)***
1
0.47(0.26-0.84)**
0.38(0.27-0.53)***
0.23(0.06-0.93)**
0.59(0.18-1.87)
0.43(0.211-0.9)**
0.65(0.26-1.57)
|
|
Community poverty
Low
high
|
-
-
|
-
-
|
1
1.35(1.10-1.67)
|
1.18(0.95-1.47)
|
|
Community education
low
high
|
|
|
1.13(0.92-1.40)
1
|
1.07(0.86-1.33)
1.13(.92-1.40)
|
|
Random effect
MOR
ICC%
PCV%
|
1.86
16.4
Reference
|
1.61
10.6
26
|
1.33
8.3
41.2
|
1.29
8
47.4
|
|
Model fitness
Log likelihood
AIC
Deviance
|
-4459
8922
8918
|
-4070
8182
8140
|
-4130
8291
8260
|
-4038
8141
8076
|
|
Spatial SaTScan analysis
A total of 5 clusters were identified and three of them were significant cluster with p-value <0.05. A total of 42 location/spot with total sampled population of 793 were found as primary cluster areas were identified using sat scan analysis with p- value < 0.000001. The primary cluster spatial window was located mainly in Somali region and 402 cases were found among the total population.(Table 4)
Table 4 SaT scan report on significant clusters of short birth interval (EDHS 2016), Ethiopia
Types of clusters
|
Num. of location
|
Coordinate/radius
|
population
|
case
|
RR
|
LLR
|
p-value
|
Primary clusters
|
42
|
7.453674 N, 46.955230 E)/ 546.25 km
|
793
|
402
|
2.02
|
103.69736
|
0.0001
|
Secondary cluster
|
75
|
11.845228 N, 41.915793 E/ 259.44 km
|
851
|
301
|
1.31
|
12.531635
|
0.0025
|
Secondary cluster
|
104
|
10.259205 N, 40.558314 E / 199.30 km
|
1187
|
394
|
1.23
|
9.297747
|
0.050
|
The primary cluster spatial window was centered at 6.559519 N, 46.154797 E / 826.74 km, with a relative risk (RR) of 2.02 and log-likelihood ratio (LLR) of 103.6 at p<0.00001. It showed that women within the spatial window had 2 times more likely higher risk of short birth interval than the women outside areas of the spatial window.