Measurement characteristics of activity-related psychosocial measures in 8- to 10-year-old African-American girls in the Girls health Enrichment Multisite Study (GEMS)

Abstract

Background. This paper presents reliability and validity analyses of physical activity-related psychosocial questionnaires completed by 8- to 10-year-old African-American girls at baseline and follow-up assessments of pilot intervention studies in the Girls health Enrichment Multi-site Study (GEMS).

Methods. Two hundred ten girls participated in the GEMS 12-week pilot studies and had their height and weight measured, wore an accelerometer for 3 days and completed a measure of their usual physical activity (PA) at baseline and after the 12-week intervention. Subgroups of girls also completed physical activity-related psychosocial measures at these two time points including: (a) self-concept; (b) self-efficacy; (c) outcome expectancies; and d) preferences. Principal components analysis was conducted on the psychosocial measures obtained at baseline. Cronbach's alpha and test–retest reliability were computed. Convergent validity was assessed by correlating the baseline psychosocial measures with baseline physical activity measures and body mass index (BMI).

Results. The following sub-scales were derived: Activity Preference, Positive Expectancies and Negative Expectancies for physical activity. Physical Performance Self-Concept and Self-Efficacy for physical activity were kept as single dimensional scales. Sub-scales, derived from principal components analyses, were Activity Preference, Positive Expectancies, and Negative Expectancies for physical activity. Internal consistency estimates for the various scales were substantial to excellent (0.67–0.85), while test–retest reliability estimates were fair to moderate (0.22–0.56). Correlations between the PA psychosocial sub-scales and measured levels of activity measures showed evidence of convergent validity for the Activity Preference sub-scale, although social desirability may have influenced the significant associations observed.

Conclusions. The Activity Preference was a fairly reliable and valid measure. Further studies are needed to examine the utility of activity-related psychosocial measures in interventions to increase physical activity among preadolescent African-American girls.

Introduction

Physical activity declines dramatically during adolescence, with girls showing sharper declines than boys [1]. African-American girls, in particular, are at high risk for a sedentary lifestyle. Data from the National Growth and Health Study (NGHS) showed declines in reported physical activity during adolescence that were more pronounced in African-American girls compared to white girls [2]. Of concern, low levels of physical activity among girls may persist in adulthood and are associated with increased risk for overweight, obesity, and cardiovascular disease, which are major public health problems [1], [3]. Interventions to promote higher levels of physical activity that are designed specifically for preadolescent African-American girls are needed. The development of effective programs to increase physical activity and decrease sedentary activity among African-American girls, however, need to be based on a clear understanding of the factors that may contribute to physical activity or inactivity in this population [4].

The physical activity patterns of youth are multi-determined. Social cognitive theory is widely used as an organizing framework to understand the determinants of physical activity [5], [6]. Social cognitive theory (SCT) posits that behavior is initiated and maintained through complex interactions of personal, behavioral, and environmental factors [7]. The literature on determinants of physical activity among youth has been reviewed extensively elsewhere [6], [8]; however, among the strongest correlates of physical activity in young children are perceived physical competence, access to physical activity opportunities, parental social support for physical activity, intentions, barriers, self-efficacy, and preferences for physical activity [8]. Research with African-American youth has also shown that self-efficacy for physical activity, positive beliefs about activity, access to physical activity opportunities, and parental influences are positively associated with activity level. Little information is available, however, regarding the correlates of physical activity among African-American preadolescent girls (e.g., ages 8–10 years), since research in this area has primarily focused on early and/or older adolescent African-American girls (e.g., ages 10 and older) [9], [10], [11], [12], [13], [14], [15], [16]. Moreover, little information is available regarding the measurement of social-cognitive constructs that are hypothesized to be related to physical activity in this population.

The purpose of this paper is to examine the psychometric measurement characteristics of several activity-related psychosocial measures in 8- to 10-year-old girls. Psychosocial instruments with adequate measurement characteristics could then be used to determine correlates of physical activity in African-American girls of this age and be used to guide intervention approaches to increase physical activity. The following personal characteristics were measured: constructs of physical performance self-concept, physical activity self-efficacy, outcome expectancies for physical activity, and activity preferences were examined for their internal consistency and test–retest reliability and convergent validity was assessed using correlations with measured levels of physical activity. Although not a comprehensive list of social-cognitive characteristics, these constructs were chosen based on previous data suggesting associations with physical activity and on their potential to serve as mediators in interventions targeting physical activity change in the context of obesity prevention.