Convergent and concurrent validity of the Frankfurt Complaint Questionnaire as a screener for psychosis risk

Abstract

For the broad identification of a risk for a serious mental disorder, valid and reliable screeners are needed to detect those most likely benefitting from a time-consuming and costly in-depth clinical assessment. In the early detection of psychoses, multiple screeners for an ultra-high risk have already been suggested. Yet, no screener explicitly targets an increased risk according to the basic symptom (BS) criteria. We therefore explored the Frankfurt Complaint Questionnaire (FCQ) as a potential screener for BS in comparison to their gold-standard clinical assessment using the Schizophrenia Proneness Instrument (SPI-A/SPI-CY) by examining its convergent (agreement between screener and gold-standard, calculated by the overall percentages of agreement between FCQ and SPI-A/SPI-CY) and concurrent (degree to which a screener can identify individuals with the target condition, examined by diagnostic accuracy measures calculated using thresholds of receiver operating characteristic curves) validity. The sample consisted of 81 patients of a psychosis early detection service (41 with an at-risk mental state or psychosis, and 40 with a nonpsychotic mental disorder). Only two visual perception disturbances reached a beyond chance level of agreement between FCQand SPI-A/SPI-CY. For the BS-criteria 'cognitive perceptive basic symptoms' and 'cognitive disturbances', only insufficient agreement between assessment techniques were detected with Cohen's kappa being 0.228 and 0.130, respectively, with an overestimation by the FCQ. Diagnostic likelihood ratios indicated only a clinically irrelevant increase in the probability of detecting BS criteria, thus, the concurrent validity of both the total of all and of only criteria-relevant FCQ-items was insufficient.Both concurrent and convergent validity of the FCQ were poor, and the FCQ dramatically overestimated clinician-assessed risk. Our results suggest that the FCQ should not be used as a screener for BS-criteria and that the convergent validity is not guaranteed on the basis of face validity alone, but has to be formally assessed.

Psychotic conversion of individuals at ultra‐high risk for psychosis: The potential roles of schizotypy and basic symptoms

“…Although the reliability of self-reported measurements largely depends on the individuals' insight into their own experiences, a selfreport format still has its own advantage of being able to assess the , 2016). Lacking this assurance, questionnaireassessed basic symptoms have consistently been reported to correspond to their interview-assessed counterparts poorly (Maß et al, 1997;Michel, Kutschal et al, 2017). Furthermore, since the selection of basic symptoms in the basic symptom criteria and the FCQ-S greatly differ, respectively, this may further limit the comparability of our results with early detection studies on basic symptoms.…”

Estados clínicos de alto riesgo para esquizofrenia y otras formas de psicosis: una breve revisión.

“…Investigaciones realizadas con éste y otros cuestionarios autoadministrados, demuestran que tienden a sobrevalorar los síntomas en las poblaciones estudiadas (89)(90)(91).…”

The Frankfurt Complaint Questionnaire for self‐assessment of basic symptoms in the early detection of psychosis—Factor structure, reliability, and predictive validity

“…The 98 dichotomous FCQ items partially overlap with each other and refer to identical underlying BS, for example, a disturbance of receptive speech (BSABS‐item C.1.6) is targeted by as much as seven different FCQ items (no. 37, 40, 69, 82, 90, 93, and 94; Michel, Kutschal, Schimmelmann, & Schultze‐Lutter, ). The FCQ has become the main BS questionnaire, as it was used in several different cultural contexts and was translated into seven languages (Michel, Kutschal, Schimmelmann, & Schultze‐Lutter, ; Moritz et al, ).…”

“…37, 40, 69, 82, 90, 93, and 94; Michel, Kutschal, Schimmelmann, & Schultze‐Lutter, ). The FCQ has become the main BS questionnaire, as it was used in several different cultural contexts and was translated into seven languages (Michel, Kutschal, Schimmelmann, & Schultze‐Lutter, ; Moritz et al, ). Furthermore, it is still the most extensive self‐report BS questionnaire used.…”

“…Furthermore, it is still the most extensive self‐report BS questionnaire used. Yet, despite its development based on the BSABS, the FCQ items hardly capture the same phenomena as interview‐assessed BS (Mass, Krausz, & Gross, ; Michel et al, ).…”