This was a population-based prospective cohort study of the prevalence of antisocial behaviors and associated comorbid conditions (eg, asthma) among Puerto Rican children in each of two sites. Children in the South Bronx (New York) and the standard metropolitan areas of San Juan and Caguas (Puerto Rico) were enrolled from July 2001 through August 2003. The study was approved by the Institutional Review Boards of the New York State Psychiatric Institute and the University of Puerto Rico Medical School.
The study employed a multistage probability sample design described in detail elsewhere. Briefly, primary sampling units were randomly selected neighborhood clusters based on the 1990 US Census and subsequently adjusted to the 2000 census. Secondary sampling units were randomly selected households within each individual primary sampling unit. To contrast the prevalence of antisocial behaviors between island and mainland Puerto Rican children (the primary purpose of the original study), the sample size was calculated to be 1101 children per site in order to detect a risk ratio of 1.5 with 80% power at a p value <0.05.
A household was eligible if as follows: (1) at least one resident was a child between the ages of5 and 13 years who was identified by his/her parents/primary caretakers as being of Puerto Rican background, and (2) at least one of the child’s parents or primary caretakers in the household also self-identified as being of Puerto Rican background. In households with more than one eligible child, a maximum of three children were randomly selected to participate. Children were not eligible if they had mental retardation or developmental disabilities, or if they had not resided in the household for at least 9 months.
Families were invited to participate by trained interviewers who visited each randomly selected household. Initial contact was attempted up to six times per household. Informed consent was obtained from the parents of each participant. Structured questionnaire interviews were conducted in English and/or Spanish based on the preferences of the participants.
All measures included in this analysis were based on parent/ guardian responses to interview questions. The study instrument was part of the Service Utilization and Risk Factors interview that was developed for the Epidemiology of Childhood and Mental Disorders Study for the purposes of assessing the presence of risk factors associated with mental illness. Psychometric properties of the specific components of the Service Utilization and Risk Factors interview (ie, medical history, sociodemographics) and methods used for cross-cultural adaptation and translation have been described elsewhere. Demographic data included the child’s age, gender, birthplace of the participants, birthplace of all grandparents of the participants, and indicators of socioeconomic status (SES) such as household income, use of public assistance, parental education, and parental marital status. Prenatal and perinatal information included gestational age, prenatal substance use by the mother, and perinatal complications. Information on the medical history and health-care use of the child was obtained. Parents were asked to respond “yes” or “no” to the questions “has your child ever had asthma?” and “has your child ever been hospitalized for asthma?”
The samples were weighted to represent the age and gender distribution of the populations of Puerto Rican children in the South Bronx and the standard metropolitan areas in Puerto Rico on the basis of the 2000 US Census. Weighted analysis was conducted (SUDAAN Software, Version 8; Research Triangle Institute; Research Triangle Park, NC) to adjust SEs for intraclass correlations induced by multistage sampling, with children nested within households and households nested within primary sampling units. We used bivariate logistic regression to examine potential predictors of asthma and hospitalization for asthma. Multivariable logistic regression models were constructed by entering all bivariate predictors with p < 0.20 followed by a backward stepwise selection procedure. Our primary predictors of interest were area of residence and birthplace. Other covari-ates remained in the final models if they were statistically significant (p 10% change in the measure of association).