Further Evidence for a Dimensional Latent Structure of Health Anxiety: Taxometric Analyses of the Whiteley Index Based on Two German Representative Samples

Health anxiety is an intricate part of illness anxiety and somatic symptom disorder. Based on convenience samples, two out of three available studies indicate that it is a dimensional rather than a categorical construct. Using two representative datasets, this study investigates whether previous results can be clarified. Conventional taxometric analyses as well as comparison curve fit indices (CCFI) profile analyses (MAMBAC and MAXSLOPE procedures) were calculated with two datasets of the German adult population assessing the Whiteley Index (WI-14, N = 2,072; WI-7, N = 2,498). Mean CCFIs indicated a dimensional structure for both the WI-7 (mean CCFI = 0.42, mean CCFI profile = 0.40) and the WI-14 (mean CCFI = 0.44, mean CCFI profile = 0.32). The results support and extend previous findings by strongly suggesting a dimensional distribution of health anxiety in the general population. Implications for research and practice comprise the adoption of a dimensional description of psychopathology as well as transdiagnostic treatment approaches.

Distribution of health anxiety in a general adult population and associations with demographic and social network characteristics

BACKGROUND

Health anxiety (HA) is associated with increased risk of disability, increased health care utilization and reduced quality of life. However, there is no consensus on which factors are important for the level of HA. The aim of this study was to explore the distribution of HA in a general adult population and to investigate whether demographic and social factors were associated with HA.

METHODS

This study used cross-sectional data from the seventh Tromsø study. A total of 18 064 participants aged 40 years or older were included in the analysis. The six-item Whiteley Index (WI-6) with a 5-point Likert scale was used to measure HA. Sociodemographic factors included age, sex, education, household income, quality of friendship and participation in an organized activity.

RESULTS

HA showed an exponential distribution among the participants with a median score of 2 points out of 24 points. In total, 75% had a total score of 5 points or less, whereas 1% had a score >14 points. Education, household income, quality of friendship and participation in organized activity were significantly associated with HA. The variable quality of friendship demonstrated the strongest association with HA.

CONCLUSION

Our study showed an exponential distribution of HA in a general adult population. There was no evident cut-off point to distinguish participants with severe HA based on their WI-6 score, indicating the importance of analysing HA as a complex, continuous construct. HA demonstrated strong associations with quality of friendship and participation in an organized activity.

Psychometric Evaluation of the Whiteley Index-8 in Chinese Outpatients in General Hospitals

Background: Excessive and persistent health anxiety is a common and disabling but often unrecognized illness. Therefore, screening patients for health anxiety is recommended in primary care. The aim of the present study was to examine the psychometric properties of an updated version of the eight-item Whiteley Index (WI-8) among outpatients in general hospitals in China. Methods: The presented data were derived from a multicenter cross-sectional study. The Chinese version of the WI-8 was administered to a total of 696 outpatients. Cronbach's alpha was used to evaluate the internal consistency of the scale. The validity of the scale was evaluated based on factor analysis and correlation analyses. To assess the discriminant ability, receiver operating characteristic (ROC) analysis was conducted. Results: Cronbach's alpha was 0.937, and it decreased (0.925) after deleting the new 8th item. Factor analysis extracted one factor accounting for 69.2% of the variance. Moderate correlations were found (0.414-0.662) between the WI-8 and General Anxiety Disorder (GAD-7), Patient Health Questionnaire-9 (PHQ-9), Patient Health Questionnaire-15 (PHQ-15) and Somatic Symptom Disorder B-criteria (SSD-12). The ROC curve indicated excellent discriminatory ability to discriminate among patients with health anxiety (AUC = 0.822). Conclusions: The new WI-8 version is a reliable and valid tool to screen for health anxiety in general hospital patients. We recommend the WI-8 as a useful screening tool for health anxiety.

The Whiteley Index-6: An Examination of Measurement Invariance Among Self-Identifying Black, Latino, and White Respondents in Primary Care

Brief measures that are comparable across disparate groups are particularly likely to be useful in primary care settings. Prior research has supported a six-item short form of the Whiteley Index (WI), a commonly used measure of health anxiety, among English-speaking respondents. This study examined the measurement invariance of the WI-6 among Black ( n = 183), Latino ( n = 173), and White ( n = 177) respondents seeking treatment at a U.S. community health center. Results supported a bifactor model of the WI-6 among the composite sample ( N = 533), suggesting the presence of a general factor and two domain-specific factors. Results supported the incremental validity of one of the domain-specific factors in accounting for unique variance in somatic symptom severity scores beyond the general factor. Multiple-groups confirmatory factor analysis supported the configural, metric, ands scalar invariance of the bifactor WI-6 model across the three groups of respondents. Results provide support for the measurement invariance of the WI-6 among Black, Latino, and White respondents. The potential use of the WI-6 in primary care, and broader, settings is discussed.

The Hordaland Health Study (HUSK)

OBJECTIVE

The Whiteley Index (WI) is a widely used screening instrument for health anxiety/hypochondriasis. Several studies have previously explored the psychometric properties of the WI, but with mixed findings concerning both item composition and factor structure. The main aim of the current study was to examine different factor structures as identified from previous studies using data from a large general population based study. We also wanted to provide gender specific norms.

METHODS

Data were taken from a large population-based study in Norway, the Hordaland Health Study (HUSK N=7274). Confirmatory factor analysis (CFA) of several models of the WI was conducted. Item response theory (IRT) analysis was performed on the model with the best goodness-of-fit.

RESULTS

CFA of all previously proposed factor models of the WI revealed clearly inadequate model fits. The IRT analysis suggested that a six-item model best described the data, and CFA confirmed an adequate goodness-of-fit across indices.

CONCLUSION

The current study found evidence for a six-item, single-factor model of the WI. Our findings suggest that this abbreviated version has the best factor structure compared to previously proposed factor models. We recommend that the factor structure identified in this study should be investigated further in independent samples.

A community-based epidemiological study of health anxiety and generalized anxiety disorder

This community-based study examined the frequency of worry about personal health in respondents with and without generalized anxiety disorder (GAD), and the impact of health anxiety on the disorder. A random community-based telephone survey of 5118 Chinese respondents aged 18-64 was conducted. A fully structured questionnaire covered the DSM-IV-TR criteria of GAD, major depressive episode (MDE), eight domains of worry, the seven-item Whiteley Index (WI-7), health service use, and socio-demographic information. Worry about personal health ranked fifth (75.6%) among eight domains of worries examined. GAD respondents with high level of health anxiety were significantly older, less educated, and had lower family income. High health anxiety significantly increased the occurrence of one-year MDE, previous persistent worry, previous persistent low mood, number of domains of worries, number of non-core DSM-IV-TR GAD symptoms, health service use, and mistrust of doctors. Health anxiety is common in GAD and may signify greater severity of the disorder.