Development of the Perceived Risk of HIV Scale

Authors: Lucy E Napper Dennis G Fisher Grace L Reynolds

Publish Date: 2011/07/22

Volume: 16, Issue: 4, Pages: 1075-1083

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Abstract

Past studies have used various methods to assess perceived risk of HIV infection however few have included multiple items covering different dimensions of risk perception or have examined the characteristics of individual items This study describes the use of Item Response Theory IRT to develop a short measure of perceived risk of HIV infection scale PRHS An item pool was administered by trained interviewers to 771 participants Participants also completed the risk behavior assessment RBA which includes items measuring risky sexual behaviors and 652 participants completed HIV testing The final measure consisted of 8 items including items assessing likelihood estimates intuitive judgments and salience of risk Higher scores on the PRHS were positively associated with a greater number of sex partners episodes of unprotected sex and having sex while high Participants who tested positive for HIV reported higher perceived risk The PRHS demonstrated good reliability and concurrent criterionrelated validity Compared to single item measures of risk perception the PRHS is more robust by examining multiple dimensions of perceived risk Possible uses of the measure and directions for future research are discussedEstudios previos han utilizado varios métodos para evaluar los riesgos percibidos de la infección del VIH sin embargo pocos han incluido los varios elementos que cubren las diferentes dimensiones de la percepción del riesgo o han examinado las características de los elementos individuales Este estudio describe el uso del “Item Response Theory” IRT para desarrollar una medida básica del riesgo percibido de la infección del VIH PRHS A 771 participantes se les administro un sorteo de elementos a mano de entrevistadores calificados Los participantes también rellenaron evaluaciones de riesgo que incluyen elementos para evaluar comportamiento de riesgo sexual y 652 de los participantes tomaron pruebas para el VIH La medida definitiva constaba de 8 elementos elementos que incluyeron la evaluación de la estimación de probabilidad juicios intuitivos prominencia de riesgo Las puntaciones más altas fueron asociadas con un número más elevado de parejas sexuales relaciones sexuales sin protección y relaciones sexuales bajo el influjo Los participantes que resultaron seropositivos para el VIH reportaron niveles altos de riesgo percibido El PRHS demostró buena fiabilidad y validez de criterio relacionado concurrente En comparación con los métodos de evaluación del riesgo percibido de un solo elemento el PRHS es más robusto en examinar dimensiones múltiples de riesgo percibido Usos posibles de la evaluación y direcciones para investigaciones en el futuro son discutidosBeliefs about personal risk for HIV infection are central to understanding what motivates people to engage in behaviors that reduce or increase their risk of HIV infection Centers for Disease Control and Prevention guidelines for HIV testing and counseling include HIV risk assessments to enhance selfperception of risk 1 and HIV/AIDS interventions often aim to influence how people perceive their risk of HIV infection 2 3 4 5 Models such as the Protection Motivation Theory 6 Health Belief Model 7 Social Cognitive Theory 8 Extended Parallel Process Model 9 and the AIDS Risk Reduction Model 10 all include perceived risk as an important predictor of risk behaviors Although perceived risk alone is not sufficient to motivate attitude or behavior change it is seen as necessary for changeIn a recent review of behavioral interventions to reduce HIV risk behaviors 11 15 out of 38 studies reported examining or enhancing perceived risk Although the construct of perceived risk is often measured other than reporting reliability few studies report the psychometric properties of the risk perception measures they employ 12 13 Accurate measures of risk perception are needed to examine how people think and feel about risk how perceived risk relates to behavior and actual HIV infection and how effective interventions are at enhancing perceived risk 12Existing measures of perceived risk of HIV infection often rely on single items 14 15 16 A single item may not adequately capture how people think and feel about their risk of contracting HIV A review of past research revealed that perceived risk for HIV infection has largely been operationalized as a cognitive assessment of risk such as the probability chance or likelihood of becoming infected with HIV 17 However there is an increasing recognition of the role of affective or intuitive processing in how people think about risk 12 18 19 20 21 Dualprocess theories 22 suggest people think about their risk both in an analytical deliberative way and in a more intuitive affectivebased manner 19 Acknowledging that the risk of HIV is a possibility without feeling at risk may not be sufficient to motivate behavior change 23 Another dimension of perceived risk that is important for understanding how people think about their risk is the salience of the risk or how often someone thinks about the risk 20 21 24 25 There have been calls for broader conceptualization and measures of risk perception 21 and more research to understand how best to measure HIV risk perception 26 Researchers have begun exploring approaches to measuring risk perception in other domains such as skin cancer 12 and influenza vaccination 27 however there is a lack of research examining how best to measure perceived risk for HIV infectionThe current study aimed to develop a measure that combines different approaches to measuring perceived risk including likelihood estimates intuitive feelings about risk and the salience of the risk of HIV infection To aid in scale development Item Response Theory IRT was used to examine the psychometric properties of individual items IRT is a set of models that describes the probability of responding to an item response category as a function of the respondent’s level on the trait being assessed θ theta and characteristics of the item for example item difficulty or discrimination IRT provides a useful tool in the development of a measure because it provides information about individual items Item information functions IIFs can be used to examine how discriminating an item is as a function of perceived risk In addition option response functions ORFs provide information about the probability of an item response category being selected as a function of perceived risk and can be used to decide whether a response category is redundant and could be collapsed Unlike classical test theory where standard error of measurement is the same across all scores in a population IRT provides information about standard error of measurement across different levels of perceived risk 28The current study had the following aims 1 Develop a pool of items assessing how people think and feel about their risk of HIV infection based on their sexual behaviors 2 use IRT to examine item characteristics and construct a measure of perceived risk of HIV infection the Perceived Risk of HIV Scale PRHS and 3 examine the criterionrelated validity of the measure by exploring the relationship between perceived risk and recent sex behaviors and test results for sexually transmitted diseases Past research has used similar measures to assess perceived risk based on past behaviors 29 30 It is hypothesized that when people are asked to think about their risk of HIV infection based on their recent sex behaviors those who engage in more risky sex behaviors and those who later test positive for syphilis or HIV infection will perceive themselves to be at higher risk of HIV infectionItems were developed to assess different dimensions of risk perception based on past literature including cognitive assessments eg likelihood judgments intuitive assessments eg feeling vulnerable to HIV and salience of risk eg is HIV risk something they have thought about The original item pool of 30 items was reviewed by a group of subject matter experts SMEs N = 6 and by a focus group of individuals at risk of HIV infection men who have sex with men and current drug users N = 8 SMEs included researchers who had published in the field of HIV and risk perception SMEs were provided with a definition of the construct a description of the aim of the study and of the target sample SMEs were asked to rate each item for relevance to the construct and item clarity as well as to provide additional comments about item content Individuals from the focus group were interviewed oneonone while completing the items they were asked to rate how clear each question was as well as openended questions about what they understood the question to mean and any difficulties they had answering the question Based on feedback from both the SMEs and focus group items were reworded and the final item pool was reduced to 18 items focusing on the risk of HIV infection from participants’ recent sex behaviors

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