THE CEBU LONGITUDINAL HEALTH AND NUTRITION SURVEY (CLHNS) A Multipurpose Study of Mother-Child Pairs in the Philippines (a cohort or panel study)

a joint project of: University of San Carlos Office of Population Studies Fdn. Cebu City, Philippines Carolina Population Center University of North Carolina at Chapel Hill NC, USA and

Study area: Metro Cebu Study period:

Sample: a cohort of mothers and their index children born between May 1, 1983 and April 30, in 17 urban and 16 rural barangays of Metro Cebu - using a stratified cluster sampling

SURVEY ROUNDS: Baseline1983 – 1984 Birth Interview1983 – 1984 Longitudinal surveys – 1986 First follow-up survey1991 – 1992 Second follow-up survey1994 – 1995 Third follow-up survey1999 – 2000 Fourth follow-up survey2002 – 2003 Fifth follow-up survey2005

PURPOSE OF THE SURVEYS: 1983 – 1986Study child care and infant feeding practices 1991 – 1992 Monitor the growth of children 1994 – 1995a) Study womens autonomy, family planning use and labor force participation b) Examine the relationship between childrens nutritional status and school performance 1999 – 2000Study adolescents reproductive health, sexual behavior and parent communication

2002 & 2005 Examine how childhood health and nutritional status affect educational attainment, work patterns and wages of young adults

Number of mothers interviewed at selected time points in the CLHNS: Baseline3,327 (100%) Birth interview3,051 (91.7) Longi 122,555 (76.8) 1991 Follow-up2,395 (72.0) 1994 Follow-up2,279 (68.5) 1999 Follow-up1,991 (59.8) 2002 Follow-up2,102 (63.2) 2005 Follow-up2,060 (61.9)

Number of children studied: Baseline/Birth interview:3,080 single live births 51 stillbirths/miscarriages 17 multiple births 179 lost/migrated/refused Longitudinal survey 122,550 (82.8%) 155 infant/child deaths With inclusion of some multiple births: 1991 Follow-up2,261 (73.0) 1994 Follow-up2,181 (70.4) 1999 Follow-up2,089 (67.5) 2002 Follow-up2,051 (66.2) 2005 Follow-up1,912 (61.7)

Approximate ages of mothers and children: MothersChildren Baseline/Birth Interview Longitudinal Survey Follow-up Follow-up Follow-up Follow-up Follow-up

Compared to all ever-married women in Metro Cebu during the 1980 Census, the CLHNS mothers were: - Younger - Had more children - Less likely to have completed college CLHNS mothers who dropped out of the survey were more likely to be: - Younger - Primiparous or of low parity - With more years of education - In the labor force

Survey components/modules: A.Core modules Demographic – HH composition, pregnancy history, knowledge and use of family planning Socioeconomic – HH income, assets and expenditures Environmental – water source, sanitation and hygiene, type of settlement Diet – 24-hr food recall of mother and child Anthropometry – weight, height, arm, waist and hip circumference Community characteristics – infrastructure, facilities, prices and wages

B. Age-specific/special interest modules: - Childrens IQ and school achievement scores (1991/1994) - Domestic violence, womens status and decision-making (1994 – 2005) - In-depth interviews of mothers on FP, decision-making, employment (1994) - In-depth interviews of husbands (1998) - Pubertal maturation and adolescent reproductive health (1999) - Parental views on adolescent sexual and reproductive behavior (1999) - Risk factors for cardiovascular diseases (1999/2005)

C. New modules for Event history matrix - schooling, employment, residence, sexual relationship, cohabitation & marriage, fertility, major illnesses Education training and skills requirement for young adults Health indicators relevant to young adults - STDs and risk-taking behavior Body image Measures of psychological wellbeing Financial autonomy Activities of daily living Memory test for mothers Blood samples, saliva samples

The CLHNS data have been used in at least 75 publications 20 doctoral dissertations Data are available in: CD-ROM (stata format) - request from OPS World Wide Web (1991 and 1994 surveys)

Some substantive contributions of the CLHNS: Determinants of birth outcomes Infant morbidity, mortality and growth Infant feeding practices – breastfeeding, role of media and marketing of infant formula Consideration of environmental factors such sanitation and water quality on infant health Birth spacing and postpartum amenorrhea Child growth and development – stunting, wasting and growth retardation and effects on cognitive test performance of children Reproductive health and sexuality – unmet need for adolescent health care Womens work health and nutrition Domestic violence Husbands perceptions on family planning and wives work participation Health effects of urbanization Sexual initiation, and transition to marriage

Future direction: Application of intergenerational cohort analysis CVD risk factors clustering in mothers and offsprings amidst rapid development (nutrition transition)

Childhood Stunting and School Attainment of Filipino Young Adults (USC-OPS preliminary analysis of the 2005 survey)

Purpose of the 2002 & 2005 surveys: Examine how childhood health and nutritional status affect educational attainment, work patterns and wages of young adults Purpose of the current analysis: Explore long term effects of early childhood stunting on school attainment and work status in young adulthood.

Previous studies using CLHNS data have shown that undernutrition (stunting) of Filipino children at age 2 years have adverse effects on age at entry into school, grade repetition, and grade completion up to high school (Daniels & Adair, 2004; see also Mendez & Adair, 1999; Glewwe and King, 1991) Recent data permits the examination of the effect of stunting or growth retardation at age 2 on education up to the tertiary level. Main exposure variable: Stunting - based on height-for-age Z-score of < -2 SD based on the WHO/NCHS standard.

Outcome measures: 1)Final grade/year completed (continuous) 2)Completion of high school (binary) 3)Completion of college (binary) Confounding/control variables: -Mothers age -Mothers education -Number of siblings -Household asset score (1-6) -Urban/rural classification Mediating variable: IQ test score at age ~8 years

Statistical models: Linear regression and logistic regression Analysis stratified by sex -1,859 index children in complete information in 2005 (969 males, 890 females)

Profile of CLHNS Sample by Sex More females stunted at age 2, but more females have completed high school and college

Odds of being included in analysis Sample attrition did not introduce bias with respect to these characteristics

Linear Regression Models: Final grade/year completed For both sexes, stunting at age 2 is associated with lower school attainment. The effect of stunting is stronger in females than males. IQ mediates some of the effects of early childhood stunting on school attainment. The attenuating effect of stunting on school attainment is larger for females than males.

Logistic regression: High school completion and College completion With the mediating effect of IQ, stunting at age 2 is not associated with high school completion for both sexes but is associated with reduced Likelihood of college completion among females.

Summary of preliminary findings Stunting at age 2 is associated with lower school attainment for both sexes Effect of stunting is stronger in females than in males IQ is a mediating factor of the effect of early childhood stunting on school attainment - this influence is stronger in females than males Stunting is associated with reduced likelihood of college completion among females

Height-for-age in Early Childhood and Work Status of Young Filipino Adults (USC-OPS preliminary analysis of the 2005 survey)

Outcome variable Work status in 2005 defined as: 0 - not working 1 - working in the informal sector 2 - working in formal sector i.e., a) hours worked >= 40 hours/week b) pay is >=P 173/day (~$3.46),and c) benefits from SSS/GSIS/PhilHealth other health insurance or PagIBIG Exposure variable Height-for-Age Z-Score (HAZ) at two years old

Confounders: birth weight mothers schooling attainment household location (urban-rural) ownership of assets Stratified by: Sex Mediating factor: Last grade/year completed Statistical model: Multinomial logistic regression

Summary of preliminary findings: HAZ is positively associated with formal sector work relative to not working among males HAZ is positively associated with formal versus informal sector work among females The association between HAZ and formal sector work is primarily mediated by educational attainment (i.e., HAZ loses significance for females, and is significant only at p<.15 for males)

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