author author author ph251 date is father absence early in life associated with age at menarche?
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Author Author Author
PH251 Date
Is Father Absence Early in Life Associated with
Age at Menarche?
Overview
IntroductionMethodsResultsDiscussion
Research Question
Is father absence at age 5 associated with age at menarche in the California Child Health and Development Studies (CHDS) Cohort?
Background
Public Health Implications of Earlier Menarche: Breast cancer, obesity, type II
diabetes Conduct & behavioral disorders Substance Abuse Depression & Eating Disorders Teen Pregnancy
Background
Average age about 12 1/2 But wide variation Variation depends on:
Race/ethnicityMaternal Age at MenarcheBMIFamily Environment Early in Life
Father AbsenceSibling Composition
Father Absence Theories
Psychosocial Acceleration Theory
Chemosignal (Phermone) Theories
Paternal Investment TheoryEnergetics TheoriesLife History Theory
Hypotheses
Girls with father absence at age 5 will have earlier age at menarche.
Father absent girls with more siblings will have a later age at menarche than father absent girls with less siblings.
Review of the Literature
Several studies found association
Campbell & Udry (1995) did NOT find this effect at age 5 in CHDS cohort…WHY NOT? Strange covariates in model? Statistical models used? Effect modification?
Overview
IntroductionMethodsResultsDiscussion
Study Participants
20,754 pregnancies in the CHDS
3,587 live, female births with no congenital anomalies born between June 1960 and January
1963
850 participated in five year 1, nine to eleven, and adolescent
examinations
748 provided information on father absence at age 5, age at menarche, and sibling composition
at age 5
Exposure
Father absence at age 5: Five Year 1 Examination Based on maternal report “Mother only” or “Mother +
Stepfather”
Outcome
Age at menarche Adolescent Examination Self-reported Years, not months
Covariates
Chosen a priori from the literature: Race Maternal age at menarche Social class BMI – mediator Siblings (total #, older male, older female)
Confounders included in statistical model if their removal changed the coefficient on father absence by ≥ 10%
Statistical Analysis
Statistical Models Linear regression Logistic regression Polytomous logistic regression Cox proportional hazards regression
Effect Modification Sibling composition Race
Sensitivity Analysis
Overview
IntroductionMethodsResultsDiscussion
Descriptive Statistics
93%
7%
Number & Percent of Girls with Father Absent
& Present at Age 5
Father Present(n=695)
Father Absent(n=53)
60%
15.8%
24.2%
Percent of Girls with Early, Normal & Late
Menarche Normal Menarche(12-13)Early Menarche(< 12)Late Menarche(> 13)
Covariates Associated with Father Absence
Race Maternal age at menarche Social class BMI Total # of Siblings Total # Older Brothers Total # Older Sisters
Covariates Associated with Age at Menarche
Race Maternal age at menarche Social class BMI Total # of Siblings Total # Older Brothers Total # Older Sisters
Crude Association
No difference in mean age at menarche by exposure (P = 0.5) Father absent girls: 12.6 Father present girls: 12.7
Multivariate Model Results
Dichotomous Logistic Regression: OR=1.4 (0.6, 2.9)
Polychotomous Logistic Regression: OR=1.3 (0.6, 2.8) (Early vs. Normal) OR=0.9 (0.4, 1.9) (Late vs. Normal)
Multivariate Linear Regression: β=-0.2 (-0.5, 0.2)
Cox Proportional Hazard Regression: HR=1.0 (0.4,1.8)
Interaction
Interaction terms tested using all our modeling approaches. Father absence x number of siblings Father absence x number of older sisters Father absence x number of older brothers Father absence x race
No evidence of interaction. All p-values > 0.5
Sensitivity Analysis
Recoded individuals living with “grandparents” and “other” as father absent.
Included individuals missing sibling information at age 5 and age 9-11.
Used maternal age at menarche data from just the BASIC dataset and just the PNWORK dataset.
Overview
IntroductionMethodsResultsDiscussion
Findings
Findings do not support father absence/sibling theories
Findings do not support most other literature
Findings DO support Campbell & Undry’s findings from 1995
Strengths
Sample size Study Design Statistical Methods
Multiple Multivariate Regression Models
Covariates Considered Interactions Considered Sensitivity Analyses
Limitations
Recall Bias Father Absence Variable
Small n Time of father absence unknown Stepfather presence not considered
Pubertal Timing Indicator SES Variable Quality of Family Relationships
Future Research
MEASURE STRESSMEASURE
PUBERTAL ONSET
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