Puerto Rican Maternal and Infant Health Study (PRMIHS), 1994-1995 (ICPSR 36238)

Principal Investigator(s): Landale, Nancy, Penn State Population Research Institute; Oropesa, R. Salvador, Penn State Population Research Institute; Davila, Ana Luisa, University of Puerto Rico


The Puerto Rican Maternal and Infant Health Study (PRMIHS) is a cross-sectional study designed to provide information on the determinants of poor infant health among Puerto Ricans. The dataset features personal interview data from 2,763 mothers of Puerto Rican infants sampled from the 1994 and 1995 birth and infant death records of six United States vital statistics reporting areas (Connecticut, Florida, Massachusetts, New Jersey, New York City, Pennsylvania) and the Commonwealth of Puerto Rico. Mothers were contacted to participate in a Computer Assisted Personal Interview (CAPI) using the address information provided in the birth and infant death records. Respondent mothers were asked to recount their sexual history and use of contraception, age at conception, prenatal care and nutrition, substance abuse, and overall health before and during pregnancy. Details were also collected regarding migration history, family composition, partner involvement, social support structures, and receipt of any public financial assistance for food, housing, and/or medical care. Information regarding infant health and well-being was also gathered, and included respondents' reporting of recurrent health issues, required medical treatments, immunizations, and any accidents or sustained injuries. Mothers were also asked to confirm attainment of a number of infant developmental milestones, including sitting, crawling, standing, waving, and vocalization, as well as several other behaviors and abilities. Demographic information for mothers includes age, education, occupation, income, marital status, race and ethnic identity, language, and religious preference.

Access Notes

  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.


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Study Description


Landale, Nancy, R. Salvador Oropesa, and Ana Luisa Davila. Puerto Rican Maternal and Infant Health Study (PRMIHS), 1994-1995 . ICPSR36238-v2. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2015-11-16. https://doi.org/10.3886/ICPSR36238.v2

Persistent URL: https://doi.org/10.3886/ICPSR36238.v2

Export Citation:

  • RIS (generic format for RefWorks, EndNote, etc.)
  • EndNote XML (EndNote X4.0.1 or higher)


This study was funded by:

  • United States Department of Health and Human Services. National Institutes of Health. Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD032331)

Scope of Study

Subject Terms:    birth, birth records, child health, child nutrition, death records, early life conditions, health disparities, health problems, infant mortality, infants, mothers, prenatal care, social support

Smallest Geographic Unit:    state/territory

Geographic Coverage:    Connecticut, Florida, Massachusetts, New Jersey, New York City, Pennsylvania, Puerto Rico, United States

Time Period:   

  • 1994-07-01--1995-12-31

Date of Collection:   

  • 1995-08--1997-09

Unit of Observation:    individual

Universe:    Puerto Rican women who had a live birth or infant death in the study area (Connecticut, Florida, Massachusetts, New Jersey, New York City, Pennsylvania, and Puerto Rico) between July 1, 1994 and December 31, 1995.

Data Type(s):    survey data

Data Collection Notes:

For additional information on the Puerto Rican Maternal and Infant Health Study (PRMIHS), please visit the PRMIHS Web site.


Study Purpose:    To identify the determinants of infant health outcomes among Puerto Ricans.


Personal interview data were collected from 2,763 mothers of Puerto Rican infants sampled from the 1994 and 1995 birth and infant death records of six United States vital statistics reporting areas (Connecticut, Florida, Massachusetts, New Jersey, New York City, Pennsylvania) and the Commonwealth of Puerto Rico. The included U.S. states were those with the greatest number of births to Puerto Rican women each year. In 1994 and 1995, 72.3 percent of all births to mainland Puerto Rican women occurred in the included states. Mothers of the sampled infants were located from the address information provided on the vital records and asked to participate in a Computer Assisted Personal Interview (CAPI). All study interviewers were bilingual, and the questionnaire was available in both Spanish and English. Roughly two-thirds of the interviews (1,946) were with mothers of infants sampled from the computerized birth certificate files maintained by the states and Puerto Rico. The remaining 817 interviews were with mothers of infants drawn from death certificates for infant deaths.

Independent live birth and infant death samples were drawn from birth certificates and death certificates. The birth sample was stratified by vital statistics reporting area, month, and infant birth weight (less than 2500 grams; 2500+ grams). The death sample was based on the full population of infant deaths.

Time Method:    Cross-sectional


The data are not weighted. However, the dataset contains two weight variables (BIRTHWGT and DEATHWGT) which should be used in any analyses.

Birth Sample Respondent-level Weights (BIRTHWGT): All 1,946 respondents were assigned a final analysis weight which was the product of the basic sampling weight and two adjustments -- a nonresponse weight and a post-stratification weight. Nonresponse weights adjust for differential completion rates across demographic subgroups. To determine this weight, a file containing data for all respondents was weighted by the basic sampling weight. To create weighting class cells, the weighted file was then cross-tabulated by geographic area (Puerto Rico/New York City/the 5 states combined), birth weight (low/normal), and mother's age, marital status, and education. The nonresponse weight is equal to the inverse of the weighted response rate in each cell of the cross-tabulation. Next, a post-stratification weight was calculated by weighting the respondent file by the product of the sampling weight and the nonresponse weight. The same cross-tabulation described for the nonresponse weight was produced for the sample file and for the population file (the 1994 and 1995 Natality Files for the U.S. and Puerto Rico). The goal of post-stratification is to align weighted sample totals to the known population totals for specified variables. The post-stratification weight adjustment is equal to P/p for all cases in a given cell, where P refers to the proportion of the population in a given cell and p to the proportion of the weighted sample for the same cell. The final weight, to be used when analyzing data from the respondents' interviews (or when analyzing data from both the interview and the birth certificate), was the product of all three weights -- sampling, nonresponse, and post-stratification.

Death Sample Weights (DEATHWGT): Since the death sample was selected with certainty, all cases in the death sample were assigned a basic sampling weight equal to one. The only weight calculated for the death sample, and thus the final weight assigned to the respondents in the death sample, was a nonresponse weight.

The birth and death samples can be combined to conduct analyses of infant mortality. Users should be aware that a small group of infants drawn into the live birth sample died before their first birthday (n = 79). These cases should be included in analyses based solely on the birth sample; however, they should be considered death cases in analyses of infant mortality. They have valid values for both the birth and death sample weights. For analyses based on the birth sample, the 79 overlapping cases should be weighted by the birth sample weight. For analyses of infant mortality based on the combined birth and death samples, the 79 overlapping cases should be assigned the death sample weight.

Note: Post-stratification was based only on geographic location, birth weight, and the mother's age, marital status, and education.

Mode of Data Collection:    computer-assisted personal interview (CAPI)

Data Source:

The PRMIHS data set contains information from infant birth and death certificates, as well as personal interviews with mothers. Birth certificates provided information on demographic characteristics of the infant's parents, the mother's pregnancy history, pregnancy and birth complications, and characteristics of the newborn. Death certificates included information on demographic characteristics of the decedent and the underlying cause of death. Many of the data items from the birth and death certificates are included in the PRMIHS data set.

Response Rates:    Response rates for the birth and death samples were 79 percent and 74 percent, respectively.

Extent of Processing:   ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Standardized missing values.
  • Checked for undocumented or out-of-range codes.


Original ICPSR Release:   2015-09-30

Version History:

  • 2015-11-16 Two documents, a field report and a questionnaire, have been added to the collection.

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