Paul Welaga Cornelius Debpuur Cornelius Debpuur Timothy Awine 10 th INDEPTH AGM 27 th -30 th September 2010 Accra
Background � Evidence on the relationship between birth-spacing and child survival is still not clear � Recommendations for birth spacing are based on information that was available several years ago (WHO Technical report on birth spacing, 2005) � Some publications recommend waiting at least 2–3 years between pregnancies to reduce infant and child mortality � Recent studies suggested that longer birth spacing, 3 to 5 years might be more advantageous to child survival ( S. O. Rutstein, 2005)
Objectives � To compare infant mortality rates between index children with preceding birth interval of 3 to 5 and 2 to 3 years � To examine differences in neonatal mortality rates between index children with preceding birth interval of 3 to 5 and 2 to 3 years � To examine differences in under two mortality rates between � To examine differences in under two mortality rates between index children with preceding birth interval of 3 to 5 and 2 to 3 years � To examine differences in under-five mortality rates between index children with preceding birth interval of 3 to 5 and 2 to 3 years
Methods � Children of second or higher order singleton live birth (index children) born in the DSS area between 1 st January 2002 to 31 st December 2007. � Preceding birth was defined as the difference in months between the birthdates of the index and immediately preceding child � Preceding birth interval was categorised into four groups; <24, 24-35, 36-59, and 60+ months � All children registered into the system were taken into account in calculating preceding birth interval
Data � Data for the analysis come from the Navrongo Health and Demographic Surveillance System (NHDSS) � NHDSS monitors a population of about 150,000 under surveillance � � Demographic events such as births, deaths, in and out migrations, pregnancies are updated every three months � NHDSS also collects data on vaccination, education, verbal autopsy and socioeconomic status
Study setting – Fertility trends TFR 6.00 5.00 4.00 3.00 TFR 2.00 1.00 0.00 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Analysis � To examine the effect of preceding birth interval on post- neonatal, infant and under-five mortality, Cox proportional regression models were used. � Logistic regression models were used to assess the effect on neonatal mortality. � Mortality rates were expressed per 1000 live births for neonatal � Mortality rates were expressed per 1000 live births for neonatal mortality and per 1000 child years of risk for post-neonatal, infant and under-five mortality � Potential confounders controlled for: mother’s age at birth, season of birth, mother’s education, place of delivery, socioeconomic status using wealth index, survival status of immediately preceding sibling, sex, year of birth and birth order
Results � In all 15424 under-five children born between 1 st January 2002 and 31 st December 2007 were included in the analysis � 1,272 deaths were recorded � Infant mortality rate of 63.4 per 1000 person years
Background Characteristics Variable N (%) deaths (% dead) Preceding birth interval 82 (9.2) <24 months 888 (5.8) 287 (9.1) 24-35 3,168 (20.5) 621 (7.9) 36-59 7,894 (51.2) 282 (8.1) 60+ 3,475 (22.5) Sex 587 (7.7) Female 7,637 (49.5) 685 (8.8) Male 7,787 (50.5) Mother’s age at birth 27 (8.0) <20 338 (2.2) 488 (7.4) 20-29 6,637 (43.0) 554 (8.8) 30-39 6,315 (40.9) 203 (9.5) 40-49 2,134 (13.8) Mother’s education 853 (8.7) No education 9,855 (63.9) 281 (6.9) Primary/JSS 4,050 (26.3) 19 (3.9) Secondary+ 493 (3.2) 119 (11.6) Missing 1,026 (6.7)
Relative risk for univariate and multivariate models for under two mortality by preceding birth interval Univariate model Multivariate model Varaible OR [95% CI] P-value OR [95% CI] P-value (unadjusted) (adjusted) Preceding birth interval 1.27 [1.0 – 1.61] 0.053 1.25 [0.97 – 1.63] 0.089 < 24 months 1.18 [1.02 – 1.37] 0.029 1.18 [1.01 – 1.38] 0.039 24-35 24-35 1 1 1 1 36-59* 1.07 [0.92 – 1.24] 0.403 1.09 [0.93 – 1.30] 0.266 60+ Mother’s education None* 1 1 Primary/Junior Sec 0.80 [0.69 – 0.93] 0.003 0.78 [0.67 – 0.92] 0.003 Secondary+ 0.50 [0.31 – 0.79] 0.003 0.48 [0.29 – 0.78] 0.003 missing 1.49 [1.22 – 1.83] <0.001 1.21 [0.97 – 1.52] 0.094
Relative risk for univariate and multivariate models for infant mortality by preceding birth interval Univariate model Multivariate model Varaible P-value P-value HR [95% CI] HR [95% CI] (unadjusted) (adjusted) Preceding birth interval 1.32 [1.01 – 1.74] 0.043 1.29 [0.97 - 1.72] 0.078 < 24 months 1.18 [1.00 – 1.40] 0.057 1.17 [0.98 – 1.40] 0.092 24-35 1 1 - 36-59* 36-59* 1.11 [0.93 -1.31] 1.11 [0.93 -1.31] 0.241 0.241 1.12 [0.92 – 1.35] 1.12 [0.92 – 1.35] 0.257 0.257 60+ Mother’s education None* 1 1 Primary/Junior Sec 0.79 [0.67 – 0.93] 0.005 0.76 [0.63 – 0.91] 0.004 Secondary+ 0.61 [0.37 – 0.98] 0.042 0.55 [0.33 – 0.92] 0.022 missing 1.60 [1.28 – 2.00] <0.001 1.24 [0.97 – 1.58] 0.084
Relative risk for univariate and multivariate models for post neonatal mortality by preceding birth interval Univariate model Multivariate model Varaible P-value P-value HR [95% CI] HR [95% CI] (unadjusted) (adjusted) Preceding birth interval 1.43 [1.03 – 1.99] 0.034 1.41 [0.99 – 2.01] 0.055 1.45 [1.17 – 1.78] 0.001 < 24 months 1.47 [1.20 – 1.80] <0.001 24-35 1 1 36-59* 1.17 [0.95 -1.44] 0.151 1.21 [0.96 – 1.53] 0.100 60+ Mother’s education None* 1 1 Primary/Junior Sec 0.78 [0.63 – 0.95] 0.016 0.74 [0.60 – 0.92] 0.008 Secondary+ 0.59 [0.32 – 1.07] 0.080 0.54 [0.29 – 1.00] 0.051 missing 1.75 [1.35 – 2.28] <0.001 1.38 [1.04 – 1.83] 0.027
Odds Ratio for univariate and multivariate models for neonatal mortality by preceding birth interval Univariate model Multivariate model Varaible OR [95% CI] P-value OR [95% CI] P-value (unadjusted) (adjusted) Preceding birth interval < 24 months 1.13 [0.70 – 1.83] 0.620 1.1 [0.65 – 1.85] 0.720 24-35 24-35 0.69 [0.49 – 0.98] 0.69 [0.49 – 0.98] 0.037 0.037 0.69 [0.48 – 1.01] 0.69 [0.48 – 1.01] 0.054 0.054 36-59* 1 0.996 1 60+ 1.0 [0.75 -1.34] 0.93[0.66-1.30] 0.660 Mother’s education None* 1 0.173 1 Primary/Junior Sec 0.82 [0.61 – 1.09] 0.298 0.81 [0.58 – 1.13] 0.222 Secondary+ 0.65 [0.29 – 1.47] 0.202 0.57 [0.23 – 1.41] 0.220 missing 1.32 [0.86 – 2.01] 1.02 [0.62 – 1.67] 0.941
Relative risk for univariate and multivariate models for under- five mortality by preceding birth interval Univariate model Multivariate model Varaible N (%) P-value HR [95% CI] HR [95% CI] (unadjusted) (adjusted) Preceding birth interval 888 (5.8) 1.17 [0.93 – 1.48] 1.23 [0.96 – 1.58] 0.096 < 24 months 3,168 (20.5) 1.19 [1.03 – 1.36] 1.17 [1.01 – 1.36] 0.038 24-35 7,893 (51.2) 1 1 36-59* 3,475 (22.5) 1.05 [0.91 -1.21] 1.02 [0.88 – 1.18] 0.809 60+ Mother’s education None* 9,855 (63.9) 1 1 Primary/Junior Sec 4,050 (26.3) 0.83 [0.72 – 0.94] 0.78 [0.67 – 0.90] 0.001 Secondary+ 493 (3.2) 0.47 [0.30 – 0.74] 0.40 [0.25 – 0.64] <0.001 missing 2,134 (13.8) 1.47 [1.22 – 1.78] 1.24 [1.01 – 1.52] 0.045
Discussion and Conclusion � Children with preceding birth interval of 24 to 35 months had a higher risk of dying at infancy, post neonatal, under two and under five compared to 36 to 59 months � Preceding birth interval did not significantly affect neonatal mortality rates. neonatal mortality rates. � The beneficial effect of longer birth spacing becomes evident after the neonatal stage �
Discussion and Conclusion � Birth interval of <24 months is generally associated with a higher risk of dying compared to 36 to 59 months � Mother’s education contributes significantly in � Mother’s education contributes significantly in reducing child mortality
Recommendation � Generally, preceding birth interval of 36 to 59 months should be encouraged as it appears to be beneficial to child survival � Reducing births associated with preceding birth interval of <24 months could help reduce child mortality .
Limitations � The HDSS may not have covered a complete birth history for each woman. This however may form a minority of births for any individual woman and should not undermine the validity of the outcome
Acknowledgement � The chiefs and people of the Kassena-Nankana East and West districts � The director and staff of the Navrongo Health Research Centre � The Navrongo Health and Demographic Surveillance System field and computing teams � INDEPTH Network
Thank you Thank you
Recommend
More recommend
