The Validity of Proxy-Based NEO-Five Factor Inventory Data in Suicide Research: A Study of 18- to 64-Year-Old Hong Kong Chinese Who Attempted Suicide

Article excerpt

Abstract

Objective: To examine the validity of proxy-based NEO-Five Factor Inventory ratings for 18- to 64-yearold Chinese who attempted suicide.

Methods: In all, 71 suicide attempters and their proxy-informants were recruited. Data based on structured interviews with the proxy respondents were compared with data obtained from interviews of the subjects themselves.

Results: For the 71 subject-proxy pairs, the overall correlations were fair to moderate (r = 0.30-0.45; p < 0.05) in all domains, except openness-to-experience. Informants with lower education levels tended to yield data that correlated less strongly with subjects' self-reports. Spousal ratings and self-reports correlated significantly in all domains, except extraversion (r = 0.42-0.63; p < 0.05).

Conclusion: The results supported proxy-based data on NEO-Five Factor Inventory in research of suicidal behaviour in this age-group.

Key words: Personality tests; Suicide

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Introduction

Suicide is a common tragic endpoint to a number of biopsychosocial adversities. Cumulative suicide death tolls have amounted to a long-term public health problem worldwide. The design of effective suicide prevention strategies should be based on scientific research that defines and quantifies risk, and protective factors in the target population. Despite potential methodological limitations of psychological autopsy (PA), the PA method is generally regarded as the hallmark for risk factor research of suicide, when conducted in a case-control manner: it is able to elicit psychological profiles and psychosocial circumstances through systematic, in-depth, diagnostic psychosocial interviews with informants who are knowledgeable about suicide victims.1,2 The validity of proxy-based data in suicide research has been examined indirectly by applying PA protocols to suicide attempters whose risk factor profile is largely comparable to suicide victims.3,4 Results supported best-estimate methodology for assessing psychiatric diagnoses, psychosocial circumstances, and details of suicidal behaviour.3,4

Reviews of cohort and retrospective case-based studies have shown a high prevalence of personality disorders (especially borderline and antisocial personality) among suicide decedents and vice versa, but the magnitude of the relationship between personality disorders and completed suicide is constrained by several factors.5 They include: (1) reliability and validity measurement of the categorical diagnosis of personality disorder; (2) the complex interaction between personality and lifestressors; and (3) the co-morbidity of Axis I Psychiatric Disorders.6 Use of a dimensional approach to personality assessment yields combinations of personality traits that might not fit into categorical diagnostic constructs. Some of these traits have been associated with completed suicide: hostility, hopelessness, helplessness, dependency, social disengagements, and self-consciousness.7 One of the available dimensional measures of personality, namely the Neuroticism Extraversion Openness-Personality Inventory Revised (NEO-PIR), depicts the 5-factor model of personality, assessing neuroticism, extraversion, openness-to-experience (OTE), agreeableness, and conscientiousness.8 The 5 domains and 30 facet scales show substantial reliability, validity, and longitudinal stability in clinical and non-psychiatric populations even across different cultural settings.9-12 Using the NEO-PIR, some retrospective case-control studies reported the association of high neuroticism and low OTE with suicidal behaviour.13,14 To date, little is known about the validity of proxy-based data on the NEO-Five Factor Inventory (NEO-FFI), when applied to the study of suicidal behaviours.

Methods

Our sample population included all suicide attempters aged 18 to 64 years, presenting to the psychiatric consultationliaison service of a regional government-funded hospital in the New Territories East District during a 1-year period starting 1 June 2004. …