Examining convergence of retrospective and ecological momentary assessment measures of negative affect and eating disorder behaviors.

OBJECTIVE: Data gathered via retrospective forms of assessment are subject to various recall biases. Ecological momentary assessment (EMA) is an alternative approach involving repeated momentary assessments within a participant's natural environment, thus reducing recall biases and improving ecological validity. EMA has been used in numerous prior studies examining various constructs of theoretical relevance to eating disorders.
METHOD: This investigation includes data from three previously published studies with distinct clinical samples: (a) women with anorexia nervosa (N = 118), (b) women with bulimia nervosa (N = 133), and (c) obese men and women (N = 50; 9 with current binge eating disorder). Each study assessed negative affective states and eating disorder behaviors using traditional retrospective assessments and EMA. Spearman rho correlations were used to evaluate the concordance of retrospective versus EMA measures of affective and/or behavioral constructs in each sample. Bland-Altman plots were also used to further evaluate concordance in the assessment of eating disorder behaviors.
RESULTS: There was moderate to strong concordance for the measures of negative affective states across all three studies. Moderate to strong concordance was also found for the measures of binge eating and exercise frequency. The strongest evidence of concordance across measurement approaches was found for purging behaviors. DISCUSSION: Overall, these preliminary findings support the convergence of retrospective and EMA assessments of both negative affective states and various eating disorder behaviors. Given the advantages and disadvantages associated with each of these assessment approaches, the specific questions being studied in future empirical studies should inform decisions regarding selection of the most appropriate method.