Abstract: An International Comparison of Private and Public Schools Using Multilevel Propensity Score Methods and Graphics.

As can be seen from the recent Special Issue of MBR on propensity score analysis (PSA) methods, the use of PSA has gained increasing popularity for estimating causal effects in observational studies. However, PSA use with multilevel or clustered data has been limited, and to date there seems to have been no development of specialized graphics for such data. This paper introduces the multilevelPSA ( http://multilevelPSA.

Introduction to the Special Issue on Propensity Score Methods in Behavioral Research.

This issue includes six articles that present logic, methods, and models for causal analyses of observational data, in particular those based on propensity score (PS) methods. The articles include a general introduction to propensity score analysis (PSA), uses of PSA in mediation studies, issues involved in choosing covariates, challenges that often arise in PSA applications, hierarchical data issues and models, and an application in an educational testing context. In this editorial I briefly summarize each article and make a few recommendations that relate to future applications in this field: the first pertains to how propensity score (PS) work could profit by connecting it with stronger forms of randomized experiments, not just simple randomization; the second to how and why graphical methods could be used to greater advantage in PSA studies; then why it might be helpful to reconsider the meaning of the term "treatments" in observational studies and why conventional usage might be modified; and finally, to the distinction between retrospective and prospective approaches to observational study design, noting the advantages, when feasible, of the latter approach.

Longitudinal functional recovery after postacute rehabilitation in older hip fracture patients: the role of cognitive impairment and implications for long-term care.

Objective: To compare functional recovery patterns of cognitively impaired and nonimpaired older adults who had hip fracture surgeries, and to identify associated long-term care needs.

Methods: Longitudinal study (n = 231). Data were collected within 72 hours of admission to and before discharge from the postacute rehabilitation facilities and at 2, 6, and 12 months following postacute rehabilitation discharge.

Examining heterogeneity of functional recovery among older adults with hip fractures.

Objective: To examine heterogeneity in 1-year functional recovery following postacute rehabilitation among older adults with hip fracture.

Methods: Two hundred twenty-five community-dwelling older adults with hip fracture who received postacute rehabilitation in 5 rehabilitation facilities in Baltimore, Maryland, were recruited during postacute rehabilitation (baseline) and follow-up at 2, 6, and 12 months following postacute rehabilitation discharge. Functional recovery was measured by the activities of daily living (ADL) and instrumental activities of daily living (IADL) scores.

Rapid infant weight gain predicts childhood overweight.

Objective: To determine among a contemporary cohort whether rapid weight gain between birth and 6 months is associated with risk of childhood overweight and if this risk differs by ethnicity and/or breast-feeding history.

Research Methods And Procedures: This was a cross-sectional survey in 1999 to 2000 of parents/guardians of children participating in the Special Supplemental Nutrition Program for Women, Infants, and Children in New York State. Measurements were abstracted by chart review, including weight at birth and 6 months, and height and weight at time of survey and every 6 months subsequently.

Overweight trends among children enrolled in the New York State special supplemental nutrition program for women, infants, and children.

The objective of this study is to describe overweight trends in a large, multiethnic, low-income population of preschool children by race/ethnicity and examine cohort changes in body mass index (BMI) distribution. Cross-sectional data were collected January 1 through March 31, every year, from 1989 to 2003. Subjects were children aged 2 to 4 years participating in the Special Supplemental Nutrition Program for Women, Infants, and Children in New York State.

A comparative analysis of effects of early versus late prenatal WIC participation on birth weight: NYS, 1995.

Objectives: This study examined the effects of prenatal participation in the NYS WIC Program on birth weight through enhanced control of selection bias and gestational age bias. Program effects were assessed separately for White, Black, and Hispanic women and subpopulations defined by values of Kotelchuck index of adequacy of prenatal care utilization.

Methods: 1995 New York State Vital Statistics records were linked to WIC certifications, administrative and check redemption files, and to the 1990 federal census of NY county level data.

Barriers to the use of WIC services.

Objectives: To identify barriers that deter parents/caretakers of infants and children enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) from taking full advantage of the services provided by the program.

Subjects/setting: A total of 3,167 parents/caretakers at 51 New York State WIC local agency sites completed a barriers survey.

Design: Sixty-eight potential barriers to WIC were identified through a literature review, five focus groups with parents/caretakers of WIC participants, and an expert review panel.