Assessing Longitudinal Invariance of the Center for Epidemiologic Studies-Depression Scale Among Middle-Aged and Older Adults.

Background and Purpose: The longitudinal invariance of the Center for Epidemiologic Studies-Depression (CES-D) scale among middle-aged and older adults is unknown. This study examined the factorial invariance of the CES-D scale in a large cohort of community-based adults longitudinally. Methods: 1,204 participants completed the 20-item CES-D scale at 4 time points 1 year apart. Structural equation modeling was used to identify best fitting model using longitudinal data at baseline and at 1-, 2-, and 3-year follow-up. Results: The 4-factor model showed partial invariance over 3 years. Two of the 6 noninvariant items were consistently noninvariant at the 3 follow-up points. Conclusion: Special consideration should be given to these 2 items when using the CES-D scale in healthy adults (45-75 years old).Keywords: depression; invariance; structural equation modeling; measurement; CES-DDeveloped by the National Institute of Mental Health Center for Epidemiologic Studies, the Center for Epidemiological Studies-Depression (CES-D) scale is one of the most commonly used measures of depressive symptoms especially in community-based studies involving adult populations (Edwards, 2010; Murphy, 2011). The CES-D scale is a depressive symptom measurement scale that requires participants to report the frequency of feeling or occurrence of each of the 20 scale items in the past week. The items have been chosen to reflect various components of depression including feelings of guilt and worthlessness, depressed mood, helplessness and hopelessness, psychomotor retardation, sleep disturbance, and loss of appetite (Radloff, 1977). Each item is rated on a 4-point scale of 0 5 rarely or none of the time (less than 1 day); 1 5 some or a little of the time (1-2 days); 2 5 occasionally or a moderate amount of the time (3-4 days); and 3 5 most or all of the time (5-7 days). For 16 items in the instrument, a higher score represent more impairment, whereas for the remaining 4 items (Items 4, 8, 12, and 16), the scores are reversed, that is, a higher score represents less impairment. Reponses to the 20 items in the CES-D scale are summed to identify the level of depressive symptoms experienced by individuals in the past 1 week. A score of 16 or more indicates depressive risk (Radloff, 1977). The 20 CES-D scale items are listed with their abbreviations and factor structure in Table 1.PSYCHOMETRIC PROPERTIES OF CENTER FOR EPIDEMIOLOGICAL STUDIES-DEPRESSION SCALEThe factor structure of the scale has been debated for many years. The first factor analysis was done by Radloff in 1977. The author conducted principal component analyses (with ones in the main diagonal) with varimax rotation of the 20-item scale for three groups of samples taken from the general population and reported four factors. These factors were interpreted as depressed affect (blues depressed, lonely, cry, sad), positive affect (good, hopeful, happy, enjoy), somatic/vegetative (bothered, appetite, effort, sleep, get going), and interpersonal (unfriendly, dislike). Figure 1 shows the CES-D scale correlated four-factor model by Radloff (1977).The four-factor structure by Radloff (1977) has been replicated in other studies (Devins et al., 1988; Golding & Aneshensel, 1989; Knight, Williams, McGee, & Olaman, 1997; Roberts, 1980; Roberts, Vernon, & Rhoades, 1989). However, in some studies, the number of items used and the grouping of the items in to the factors varied. Other studies (Brown, Jose, Ng, & Guo, 2002; Chapleski, Lamphere, Kaczynski, Lichtenberg, & Dwyer, 1997; Guarnaccia, Angel, & Worobey, 1989; Miller, Markides, & Black, 1997) that tested the factor structure of the CES-D scale concluded that the depressed affect and somatic/vegetative items load on a single factor rather than two separate factors as proposed by Radloff (1977). Additional CES-D scale factor models reported in the literature include two factors (Edman et al., 1999) and seven factors (Callahan & Wolinsky, 1994), with only one item loading on two of the seven factors. …