A comparison between self-report and interviewer-rated retrospective reports of childhood abuse among individuals with first-episode psychosis and population-based controls

Abstract

The typical reliance on self-report questionnaires in retrospective case-control studies of childhood abuse and psychotic disorders has been criticised, due to the potential for recall bias associated with, amongst other factors, cognitive impairments and detachment from reality, among individuals with psychosis. One way to establish if any substantial bias may exist is to examine whether the concordance of reports of childhood abuse established from retrospective self-report methods versus more comprehensive interviewer-rated assessments differ between individuals with psychosis and controls. Data from the Childhood Adversity and Psychosis (CAPsy) study were used to examine the accuracy, strength of agreement, and convergent validity of two distinct retrospective measures of childhood abuse: a self-report questionnaire (the Childhood Trauma Questionnaire; CTQ) and a comprehensive interview (the Childhood Experiences of Care and Abuse schedule; CECA). In a sample of 234 cases with first-episode psychosis and 293 controls, we found no strong evidence that the validity of the two measures differed between cases and controls. For reports of sexual and emotional abuse, we found fair levels of agreement between CECA and CTQ ratings in both groups (kappa coefficients 0.43-0.53), moderate to high sensitivity and specificity, and reasonably high convergent validity (tetrachoric correlations of 0.78-0.80). For physical abuse, convergent validity was slightly lower in cases compared with controls. Both measures can be used in future studies to retrospectively assess associations between childhood abuse and psychotic phenomena, but time-permitting, the CECA is preferable as it provides additional important contextual details of abuse exposure.

Keywords: Case-control study; Maltreatment; Measurement; Psychometric; Psychotic disorder; Validity.

Fig. 1

Receiver Operating Characteristic curves of the proportion of individuals who reported positive or negative histories of physical, sexual, and emotional abuse for cases and controls rated by the Childhood Trauma Questionnaire (CTQ) compared to the ratings made by interviewers on the Childhood Experience of Care and Abuse (CECA) interview (i.e. sensitivity and specificity). Established cut-offs for the CTQ were employed to represent instances of none to mild versus moderate to severe levels of abuse. The diagonal line which runs from the lower left corner to the upper right corner reflects the characteristics of a scale performing no better than chance. The better the discriminating ability of the scale, the closer the curve will approach the upper left corner.