Search PubMed⌕ Search

Biomedical subjects

Graeme Hawthorne

Publications and source records attributed to Graeme Hawthorne.

At least 19 recordsLinked to original sources
PubMed2006

Bipolar disorders in Australia. A population-based study of excess costs.

OBJECTIVE: To estimate the excess costs associated with bipolar disorders in Australia, based on prevalence (using the Mood Disorder Questionnaire (MDQ)) and associated excess burden-of-illness costs. METHODS: Using data from the 2004 South Australian Health Omnibus Survey (HOS), a weighted cross-sectional survey of 3,015 adults, excess costs were estimated from health service utilisation. RESULTS: There was a 2.5% lifetime prevalence of bipolar disorders, delineated by the MDQ. Those persons (MDQ positive) reported a significantly greater use of services and a poorer health status and quality of life than those who were MDQ negative. Using the service provision perspective, excess costs of bipolar disorders in Australia were approx $3.97-$4.95 billion. CONCLUSIONS: These results from an Australian population demonstrate the significant economic burden of bipolar disorders. Our findings emphasise the need for further evaluation of the cost-effectiveness of different treatments, or alternative means of reducing the burden borne by individuals, the health system and the general community.

Adult↗
PubMed2006

Issues in conducting cross-cultural research: implementation of an agreed international protocol [corrected] designed by the WHOQOL Group for the conduct of focus groups eliciting the quality of life of older adults.

Multi-centre and cross-cultural research require the use of common protocols if the results are to be either pooled or compared. All too often adherence to protocols is not discussed in reports and where it is reported poor adherence is frequently noted. This paper discusses the use of international guidelines developed by WHOQOL Field Centres to conduct and report focus groups aimed at eliciting key concepts of quality of life among older adults. This was the first step in the development of the WHOQOL-OLD instrument. Although there was overall adherence to the agreed guidelines, there were some differences in the level of reporting, even after participating Field Centres had the opportunity to explain their reports. The reasons for these discrepancies are reported. It is concluded that because of local situations, it is difficult to achieve identical implementation of multi-centre cross-cultural protocols and that the highest standards of auditing are required if findings are to be compared. Suggestions for how such protocols can be improved are given.

Aged↗
PubMed2006

Response categories and anger measurement: do fewer categories result in poorer measurement?: development of the DAR5.

BACKGROUND: Anger is a key long-term outcome from trauma exposure, regardless of trauma type, and it is implicated as a moderator of response to treatment. It therefore seems important that anger is assessed in both epidemiological studies of trauma sequelae and in intervention evaluation research. This study explored the measurement properties of a recently investigated anger scale, the Dimensions of Anger Reactions (DAR) Scale. In our previous study, the DAR was found to be a measure of trait anger, but although brief, the nine response categories per item may have confused respondents, suggesting fewer response categories may work equally well. Additionally, our previous analysis suggested there were two redundant items within the DAR. METHODS: Three samples of Australian veterans were used to investigate the psychometric properties associated with alterations to the response categories of the DAR; veterans who participated in the DAR validation study, those participating in group therapy programmes for post-traumatic stress disorder, and veterans participating in lifestyle programmes. Item response theory analysis was used to explore the internal properties of competing DAR models, and models were assessed against external criteria. RESULTS: The results showed that the number of item responses in the DAR exceeded channel capacity, and that response bias occurred in the second half of the instrument. We hypothesized that this was due to respondents not discriminating among the many response categories. Based on a modelling exercise in which we reduced the number of DAR items from 7 to 5 and the number of response categories from 9 to 5, validation tests showed that there was no loss of sensitivity, reliability or validity. To avoid confusion with the DAR, we have referred to the revised version of the DAR as the DAR5. CONCLUSIONS: We conclude that the DAR5, which abbreviates the original DAR to half its original length, has similar psychometric properties and is therefore to be preferred especially for use with persons who are under stress, cognitively impaired or less mature. The study findings regarding the optimum number of response categories have implications for the development of other instruments.

Adult↗
PubMed2006

Treatment for combat-related posttraumatic stress disorder: two-year follow-up.

This study reports on outcomes 2 years following completion of specialist veteran posttraumatic stress disorder (PTSD) treatment programs in 2,223 (reduced to 1,508 at 24 months) consecutive admissions. Self-report measures of PTSD, anxiety, depression, anger, alcohol use, and general functioning were obtained at admission, 6, 12, and 24 months after admission. Significant improvements were demonstrated at 6 months, with smaller gains continuing through to 24-month assessment. Within subject effect sizes of around 0.8 were obtained for PTSD and around 0.5 for anxiety and depression. Although lack of a control group limits the extent to which improvements can be attributed to the treatment program, the data suggest that specialized treatment programs for combat-related PTSD continue to be of value.

Alcohol Drinking↗
PubMed2005

Patterns of treatment response in chronic posttraumatic stress disorder: an application of latent growth mixture modeling.

This study attempts to differentiate groups of individuals who exhibit different patterns of recovery following treatment for chronic posttraumatic stress disorder (PTSD) and describes these groups in terms of relevant characteristics at program intake. A sample of 2,219 Vietnam veterans who had completed a 12-week treatment program was followed up at 6, 12, and 24 months post admission using self-report measures. With change in PTSD symptoms over time as the focus, latent growth mixture modeling was used to assign individual veterans to subgroups. A three-group solution provided the best account of the data. Two groups showed moderate and consistent improvement over time although the larger group (n = 1,380) began treatment with more PTSD symptoms and improved more quickly over time. The smallest group (n = 87) showed a substantially different trajectory, with almost no net change in symptom levels over the 24-month period. The groups also varied significantly in terms of their characteristics, with symptom severity and improvements over time reflecting greater comorbidity and younger age. The results have both research and clinical implications.

Chronic Disease↗
PubMed2005

Problem gambling in Australian PTSD treatment-seeking veterans.

This study explored gambling among Australian veterans entering posttraumatic stress treatment programs (n = 153). Twenty-eight percent reached the South Oaks Gambling Screen (SOGS) criteria for probable problem gambling, as did 17% on the DSM-IV gambling scale (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; American Psychiatric Association, 1994). Almost all problem gamblers reported gambling to escape problems in other areas of their lives. The strongest independent predictor of problem gambling was gambling weekly or more often on electronic gaming machines. There was no significant relationship between problem gambling, posttraumatic stress disorder (PTSD), anxiety, depression, or alcohol use. The study identified an entrenched gambling culture among PTSD treatment-seeking veterans, finding these veterans indulge in many different forms of gambling and that these forms are mediated by situational factors that provide both casual and formal gambling opportunities.

Australia↗
PubMed2005

Imputing missing repeated measures data: how should we proceed?

OBJECTIVE: This paper compares six missing data methods that can be used for carrying out statistical tests on repeated measures data: listwise deletion, last value carried forward (LVCF), standardized score imputation, regression and two versions of a closest match method. METHOD: The efficacy of each was investigated under a variety of sample sizes and with differing levels of missingness. Randomly selected samples from a dataset (n = 804) were used to compare the methods using t-tests. Efficacy was defined as the closeness of the estimated t-values to the true t-values from the complete dataset. RESULTS: The results suggest a reliable and efficacious basis for imputation method for repeated measures data is to substitute a missing datum with a value from another individual who has the closest scores on the same variable measured at other timepoints, or the average value of four individuals who have the closest scores on the same variable at other timepoints. The LVCF and standardized score methods performed relatively poorly, which is of concern since these are often recommended. Listwise deletion was also an inefficient missing data method. CONCLUSIONS: Researchers should consider using closest match missing data imputation. Since listwise deletion performed poorly, is widely reported and is the default method in many statistical software packages, the findings have broad implications.

Alcoholism↗
PubMed2005

Imputing cross-sectional missing data: comparison of common techniques.

OBJECTIVE: Increasing awareness of how missing data affects the analysis of clinical and public health interventions has led to increasing numbers of missing data procedures. There is little advice regarding which procedures should be selected under different circumstances. This paper compares six popular procedures: listwise deletion, item mean substitution, person mean substitution at two levels, regression imputation and hot deck imputation. METHOD: Using a complete dataset, each was examined under a variety of sample sizes and differing levels of missing data. The criteria were the true t-values for the entire sample. RESULTS: The results suggest important differences. If missing data are from a scale where about half the items are present, hot deck imputation or person mean substitution are best. Because person mean substitution is computationally simpler, similar in its efficiency, advocated by other researchers and more likely to be an option on statistical software packages, it is the method of choice. If the missing data are from a scale where more than half the items are missing, or with single-item measures, then hot deck imputation is recommended. The findings also showed that listwise deletion and item mean substitution performed poorly. CONCLUSIONS: Person mean and hot deck imputation are preferred. Since listwise deletion and item mean substitution performed poorly, yet are the most widely reported methods, the findings have broad implications.

Anxiety↗
PubMed2005

Bipolar I and II disorders in a random and representative Australian population.

OBJECTIVE: To assess the prevalence of bipolar I and II disorders in an Australian population. METHOD: The Mood Disorder Questionnaire (MDQ) was administered to 3015 respondents in a random and representative sample in South Australia. Health status, quality of life and demographic data were also collected. RESULTS: There was a 2.5% lifetime prevalence of bipolar I and II disorders delineated by the MDQ. Those people had a significantly greater use of services and a poorer health status and quality of life than those who were MDQ-negative. CONCLUSIONS: These results in an Australian population are consistent with other international studies showing a greater prevalence of bipolar disorders than hitherto appreciated.

Adult↗
PubMed2005

Population norms and meaningful differences for the Assessment of Quality of Life (AQoL) measure.

OBJECTIVE: The Assessment of Quality of Life (AQoL) instrument is widely used in Australian health research. To assist researchers interpret and report their work, this paper reports population and health status norms, general minimal important differences (MIDs) and effect sizes. METHOD: Data from the 1998 South Australian Health Omnibus Survey (n=3,010 population-based respondents) were analysed by gender, age group and health status. Data from four other longitudinal studies were analysed to obtain estimated MIDs. RESULTS: The mean (SD) AQoL utility score was 0.83 (0.20). Gender and age subgroup differences were apparent; the mean scores for women were consistent until their 50s, when scores declined. Greater variability was observed for males whose scores declined more slowly but consistently between 40-80 years. For both genders, those aged 80+ years had the lowest scores. When assessed by health status, those reporting excellent health obtained the highest utility scores; progressive declines were observed with decreasing health status. Effect sizes of 0.13 or greater may reflect important differences between groups. A difference in AQoL scores of 0.06 utility points over time suggests a general MID. CONCLUSIONS: AQoL population norms, MIDs and effect sizes can be used as reference points for the interpretation of AQoL data. These findings add to the growing evidence that the AQoL is a robust and sensitive measure that has wide applicability. IMPLICATIONS: The availability of population norms will assist researchers using the AQoL to more easily interpret and report their work.

Activities of Daily Living↗
PubMed2005

Vision and quality of life: the development of a utility measure.

PURPOSE: To identify the content for a vision and quality of life-related utility measure (Vision Quality of Life Index [VisQoL]) for the economic evaluation of eye care and rehabilitation programs. METHODS: Focus groups of the visually impaired elicited key concepts. Based on these and previous research, 33 items were generated. These were administered to visually impaired adults (n = 70) and a representative sample of unimpaired adults (n = 86). The item bank was reduced through examination of item properties, exploratory factor (EFA), item response theory (IRT), and structural equation modeling (SEM) analyses. The resultant model was confirmed through administration to a second sample of participants. RESULTS: Focus group themes included physical well-being, social well-being, independence, self-actualization, emotional well-being, and planning and organization. Poorly performing items were eliminated on basic psychometric properties, including failure to discriminate. Next, EFA loadings were used to select items. Twelve items survived. To minimize redundancy, IRT analysis and SEM reduced the VisQoL item pool to six items (Cronbach alpha = 0.88). To confirm this model, these items were then administered to an additional 218 participants; 35% with a vision impairment. A pooled SEM analysis showed the model to have very good fit properties (root mean square error of approximation [RMSEA] = 0.000). A preliminary test of the model against visual acuity showed a significant monotonic relationship. CONCLUSIONS: The short 6-item VisQoL has excellent psychometric properties as a simple summative instrument. It can be used in its present state as a condition-specific outcome measure for the evaluation of healthcare interventions for the visually impaired. The descriptive model is also suitable for generating utility values for the economic evaluation of vision-related programs and services.

Adult↗
PubMed2004

Introducing co-ordinated care (1): a randomised trial assessing client and cost outcomes.

A program of care co-ordination (CC) in Melbourne for individuals with a history of high use of in-patient services was evaluated. The intervention involved care planning by a general practitioner (GP) and graduated case management depending on client health status. Services were purchased from pooled funds of participating health care agencies. A randomised control trial of 2,742 participants demonstrated no significant differences between the intervention and usual care group for two quality of life measures, the SF-36 and the AQoL (assessment of quality of life), and no difference in mortality rates. Total resource usage in the CC group was substantially higher, principally due to the extra costs for care planning and case management and for administering the CC model. Results conform to the higher costs typically found in other CC trials, although the failure to demonstrate improved client outcomes is less often reported. The reasons for this failure, whether in trial design, implementation, or theoretical underpinnings are explored in a companion paper.

Adolescent↗
PubMed2004

A concise measure of anger in combat-related posttraumatic stress disorder.

There is a need for a brief specific measure of anger for use in assessment of posttraumatic mental health problems. One unpublished short scale is the Dimensions of Anger Reactions (DAR; R. Novaco, 1975). This study examined the psychometric properties of the DAR using intake and 12-month data for 192 Australian Vietnam veterans with combat-related PTSD. Results showed the DAR to be unidimensional, reliable, and sensitive to change over time, and removal of two items improved the scale's properties. The DAR measures anger disposition directed towards others. Assessment of convergent validity indicated that the DAR primarily measures Trait Anger. Results suggest that the DAR is a psychometrically strong measure, potentially useful for the evaluation of anger in PTSD.

Anger↗
PubMed2004

Evaluating the health-related quality of life effects of cochlear implants: a prospective study of an adult cochlear implant program.

This paper prospectively documents the health-related quality of life (HRQoL) and social participation benefits of adult patients receiving cochlear implants in Australia and New Zealand. Thirty-four consecutively implanted patients completed the Assessment of Quality of Life (AQoL) and Hearing Participation Scale (HPS) instruments before implantation, and at 3- and 6-month follow-ups. Implantation resulted in significant improvements in AQoL and HPS scores, The effect size was 1.09 for both measures. Those in the top socio-economic tertile obtained the greatest gains. The HRQoL and social participation benefits were slightly larger than those reported elsewhere. This may be because participants used more recent technology (Nucleus 24 rather than Nucleus 22) and received auditory and self-efficacy training as part of their rehabilitation. The results suggest that cochlear implants have a large beneficial effect. They show that social and HRQoL outcomes can be parsimoniously measured using the HPS and AQoL instruments.

Cochlear Implantation↗
PubMed2004

Is the Australian National Survey of Mental Health and Wellbeing a reliable guide for health planners? A methodological note on the prevalence of depression.

OBJECTIVE: To consider whether the prevalence of depression reported in the Australian National Survey of Mental Health and Wellbeing is a reliable guide for mental health planners. METHOD: A comparison of methodologies for the detection of depression in the Australian National Survey and a South Australian survey. RESULTS: The Australian National Survey using the Composite International Diagnostic Interview (CIDI) reported considerably less depression than a South Australian survey, which used the mood module of the PRIME-MD 1000 study. Although the PRIME-MD may over-diagnose depression, it is probable that the preclusion criteria of the CIDI result in an under-reporting of depression. CONCLUSIONS: It is probable that the Australian National Survey under-estimates the prevalence of depression in the community. This has implications not only in assessing the morbidity and economic burden of depression, but also for the planning of future mental health services.

Australia↗
PubMed2003

Quality of life assessment in the community-dwelling elderly: validation of the Assessment of Quality of Life (AQoL) Instrument and comparison with the SF-36.

Measurement of Health-Related Quality of Life (HRQoL) of the elderly requires instruments with demonstrated sensitivity, reliability, and validity, particularly with the increasing proportion of older people entering the health care system. This article reports the psychometric properties of the 12-item Assessment of Quality of Life (AQoL) instrument in chronically ill community-dwelling elderly people with an 18-month follow-up. Comparator instruments included the SF-36 and the OARS. Construct validity of the AQoL was strong when examined via factor analysis and convergent and divergent validity against other scales. Receiver Operator Characteristic (ROC) curve analyses and relative efficiency estimates indicated the AQoL is sensitive, responsive, and had the strongest predicative validity for nursing home entry. It was also sensitive to economic prediction over the follow-up. Given these robust psychometric properties and the brevity of the scale, AQoL appears to be a suitable instrument for epidemiologic studies where HRQoL and utility data are required from elderly populations.

Aged↗