Methodological Challenges in Intervention Studies: The IMPEP Experience

Thursday, 10 July 2008: 11:10 AM
Luz S. Porter, PhD, RN/ARNP, FNP, FAAN , College of Nursing and Health Sciences, Florida International University, Miami, FL

Learning Objective 1: analyze at least 3 methodological challenges in intervention studies.

Learning Objective 2: discuss at least 3 modifications to experimental protocols, while maintaining the rigor of a randomized, controlled experimental design.


Developing efficacious, cost-efficient interventions is critical to addressing this growing problem of parental substance abuse, a major risk factor for child maltreatment, neglect, and multi-generational drug abuse. Our intervention, a blended Infant Massage-Parenting Enhancement Program (IMPEP), addresses these concerns by utilizing a series of intimate, interactive, psycho-educational small-group sessions in which mothers learn and enhance not only basic parenting skills, but also practice infant massage techniques directly with their babies as a key modality to maximize maternal-infant attachment (Porter & Porter, 2004).

This article highlights several lessons learned through methodological adaptations during the first two years (2004-2006) of a federally funded study based in South Florida to evaluate the effect of this intervention on maternal and infant health outcomes. Challenges included variable client censuses at urban study sites, an unforeseen lack of institutional support, cross-group contamination, variability in program delivery by project staff, and disruption of program implementation by climactic natural disasters. We discuss several modifications to our experimental protocol which maximized the recruitment and retention of a culturally diverse sample of 84 mother-infant pairs, while maintaining the rigor of a randomized, controlled experimental design, including block randomization and flexible class scheduling to accommodate the inherently disorganized lifestyle of this difficult to access population.

Many of the challenges faced in the early phase of the IMPEP study were difficult to predict. Certain factors beyond the project staff's control can only be minimized by refocusing our efforts to expand the number of study sites and increase the potential pool of study participants. If successful, the IMPEP has the potential for widespread use in outpatient drug rehabilitation programs for both new and expectant mothers. Our hopes are to identify qualitative improvements in measures of maternal psychosocial well-being, infant growth and development, as well as safety and maternal-infant interaction.