Rochelle E Watkins

Measurement of Aging Anxiety in an Elderly Australian Population

The purpose of this investigation was to modify an existing aging anxiety scale to produce an instrument specifically designed to assess aging anxiety in an elderly population. Existing instruments fail to consistently orientate aging associated threats into the future, and this poses a significant problem for the measurement of aging anxiety in the elderly population. It is proposed that this factor has confounded reports of the relationship between aging anxiety and advancing age. An existing valid and reliable instrument, the Anxiety about Aging Scale was modified for use with elderly respondents and tested on 123 independent community dwelling elderly individuals. The results indicated the modified scale provides a valid assessment of aging anxiety in the elderly.

The power of vivid experience in hand hygiene compliance

In recent years, explicit behavioural theories have been used in some research into hand hygiene behaviour. One of the most prominent of these has been the theory of planned behaviour (TPB). In this qualitative study aimed at increasing understanding of infection prevention practice in the acute care setting, TPB was identified as a suitable framework for the emergence of new insights that have the potential to improve the power of existing education and training. The theory emerging from the research was based on a finding that individual experience is of greater import than formal education in explaining hand hygiene behaviour. This indicated that exposure to vivid vicarious experience is a potential means to improving the power of existing training methods and increasing the propensity for instilling sustainable adequate hand hygiene habits.

Does smoking explain sex differences in the global tuberculosis epidemic

To date there has been no satisfactory explanation of the worldwide excess of tuberculosis (TB) notifications among adult males. We investigated the epidemiological basis for sex differences in TB notifications in high-burden countries using available group-level data. Multiple linear regression analysis was used to explore the ecological relationship between smoking and sex differences in TB notifications among high-burden countries. Cigarette consumption was a significant predictor of the sex ratio of TB notifications, and explained 33% of the variance in the sex ratio of TB notifications. Our findings suggest that smoking is an important modifiable factor which has a significant impact on the global epidemiology of TB, and emphasize the importance of tobacco control in countries with a high incidence of TB. This analysis provides support for the interpretation of sex differences in worldwide TB notification rates as indicative of true differences in the epidemiology of TB between males and females.

Timeliness of Data Sources Used for Influenza Surveillance

OBJECTIVE In recent years, influenza surveillance data has expanded to include alternative sources such as emergency department data, absenteeism reports, pharmaceutical sales, website access and health advice calls. This study presents a review of alternative data sources for influenza surveillance, summarizes the time advantage or timeliness of each source relative to traditional reporting and discusses the strengths and weaknesses of competing approaches. METHODS A literature search was conducted on Medline to identify relevant articles published after 1990. A total of 15 articles were obtained that reported the timeliness of an influenza surveillance system. Timeliness was described by peak comparison, aberration detection comparison and correlation. RESULTS Overall, the data sources were highly correlated with traditional sources and had variable timeliness. Over-the-counter pharmaceutical sales, emergency visits, absenteeism and health calls appear to be more timely than physician diagnoses, sentinel influenza-like-illness surveillance and virological confirmation. CONCLUSIONS The methods used to describe timeliness vary greatly between studies and hence no strong conclusions regarding the most timely source/s of data can be reached. Future studies should apply the aberration detection method to determine data source timeliness in preference to the peak comparison method and correlation.

Applying cusum-based methods for the detection of outbreaks of Ross River virus disease in Western Australia

BackgroundThe automated monitoring of routinely collected disease surveillance data has the potential to ensure that important changes in disease incidence are promptly recognised. However, few studies have established whether the signals produced by automated monitoring methods correspond with events considered by epidemiologists to be of public health importance. This study investigates the correspondence between retrospective epidemiological evaluation of notifications of Ross River virus (RRv) disease in Western Australia, and the signals produced by two cumulative sum (cusum)-based automated monitoring methods.MethodsRRv disease case notification data between 1991 and 2004 were assessed retrospectively by two experienced epidemiologists, and the timing of identified outbreaks was compared with signals generated from two different types of cusum-based automated monitoring algorithms; the three Early Aberration Reporting System (EARS) cusum algorithms (C1, C2 and C3), and a negative binomial cusum.ResultsWe found the negative binomial cusum to have a significantly greater area under the receiver operator characteristic curve when compared with the EARS algorithms, suggesting that the negative binomial cusum has a greater level of agreement with epidemiological opinion than the EARS algorithms with respect to the existence of outbreaks of RRv disease, particularly at low false alarm rates. However, the performance of individual EARS and negative binomial cusum algorithms were not significantly different when timeliness was also incorporated into the area under the curve analyses.ConclusionOur retrospective analysis of historical data suggests that, compared with the EARS algorithms, the negative binomial cusum provides greater sensitivity for the detection of outbreaks of RRv disease at low false alarm levels, and decreased timeliness early in the outbreak period. Prospective studies are required to investigate the potential usefulness of these algorithms in practice.

Disease surveillance using a hidden Markov model

BackgroundRoutine surveillance of disease notification data can enable the early detection of localised disease outbreaks. Although hidden Markov models (HMMs) have been recognised as an appropriate method to model disease surveillance data, they have been rarely applied in public health practice. We aimed to develop and evaluate a simple flexible HMM for disease surveillance which is suitable for use with sparse small area count data and requires little baseline data.MethodsA Bayesian HMM was designed to monitor routinely collected notifiable disease data that are aggregated by residential postcode. Semi-synthetic data were used to evaluate the algorithm and compare outbreak detection performance with the established Early Aberration Reporting System (EARS) algorithms and a negative binomial cusum.ResultsAlgorithm performance varied according to the desired false alarm rate for surveillance. At false alarm rates around 0.05, the cusum-based algorithms provided the best overall outbreak detection performance, having similar sensitivity to the HMMs and a shorter average time to detection. At false alarm rates around 0.01, the HMM algorithms provided the best overall outbreak detection performance, having higher sensitivity than the cusum-based Methods and a generally shorter time to detection for larger outbreaks. Overall, the 14-day HMM had a significantly greater area under the receiver operator characteristic curve than the EARS C3 and 7-day negative binomial cusum algorithms.ConclusionOur findings suggest that the HMM provides an effective method for the surveillance of sparse small area notifiable disease data at low false alarm rates. Further investigations are required to evaluation algorithm performance across other diseases and surveillance contexts.

Pathways to Treatment for Tuberculosis in Bali: Patient Perspectives:

The authors explored treatment-seeking behavior among people with tuberculosis (TB) in Bali, Indonesia. They conducted in-depth interviews with 5 people who had been diagnosed with TB and 6 people who were suspected of having TB but who had not yet received a diagnosis. Participants reported frequent delays in obtaining a diagnosis of TB and obtaining adequate treatment. The authors describe issues associated with treatment-seeking behavior using the following five main themes: awareness of TB—causes, symptoms, and seriousness; influence of others; treatment quality; treatment barriers and default; and stigma and fear. Their findings reinforce the importance of a comprehensive TB control program that provides quality diagnostic and treatment services, and patient and community education, and enables patient involvement in treatment.

Predictors of tuberculin reactivity among prospective Vietnamese migrants: the effect of smoking

We investigated the prevalence and predictors of positive tuberculin skin test (TST) results among prospective Vietnamese migrants. We interviewed and medically screened 1395 Vietnamese people aged over 15 years who had applied to migrate to Australia. Approximately 44% of applicants had an induration of 10 mm or more, and 18.6% had an induration of 15 mm or more. A positive tuberculin skin test at 5 mm, 10 mm and 15 mm of induration cut-points was significantly associated with age (OR 1.01-1.02 per year) and duration of smoking (OR 1.03-1.12 per year). Smoking appears to be an important factor associated with increased susceptibility to mycobacterial infection. It is not yet clear whether the increased tuberculin reactivity associated with smoking reflects an increased risk of tuberculosis among these migrants.

Heterogeneity in the spatial distribution of bacterial sexually transmitted infections

Objectives: Detailed knowledge of the spatial distribution of disease is required to inform service delivery and plan effective interventions. In order to elucidate the spatial epidemiology of three common sexually transmitted infections (STI) further, any significant spatiotemporal clustering of gonorrhoea, chlamydia or syphilis cases in New South Wales (NSW) was detected and described. Methods: Eleven years of notified STI case data were analysed. Calculation of age and sex-stratified incidence rates was followed by spatiotemporal cluster analyses to investigate differences in the epidemiology of gonorrhoea, chlamydia and syphilis. Results: More than one-third of all gonorrhoea, chlamydia and syphilis cases in NSW were detected within cluster areas. Gonorrhoea cases were the most highly clustered, followed by syphilis, then chlamydia. Clusters were highly significant and relative risk estimates ranged from 1.6 to 22.9. Conclusion: The findings establish the high degree of geographical heterogeneity in STI incidence in NSW and indicate that the postal area of residence is an important predictor of STI incidence. Geographical surveillance could be incorporated into routine STI surveillance to identify populations in need of intervention. The evidence presented in this report indicates a need to implement geography-specific and phase-appropriate STI prevention and control strategies.

Approaches to the evaluation of outbreak detection methods

BackgroundAn increasing number of methods are being developed for the early detection of infectious disease outbreaks which could be naturally occurring or as a result of bioterrorism; however, no standardised framework for examining the usefulness of various outbreak detection methods exists. To promote comparability between studies, it is essential that standardised methods are developed for the evaluation of outbreak detection methods.MethodsThis analysis aims to review approaches used to evaluate outbreak detection methods and provide a conceptual framework upon which recommendations for standardised evaluation methods can be based. We reviewed the recently published literature for reports which evaluated methods for the detection of infectious disease outbreaks in public health surveillance data. Evaluation methods identified in the recent literature were categorised according to the presence of common features to provide a conceptual basis within which to understand current approaches to evaluation.ResultsThere was considerable variation in the approaches used for the evaluation of methods for the detection of outbreaks in public health surveillance data, and appeared to be no single approach of choice. Four main approaches were used to evaluate performance, and these were labelled the Descriptive, Derived, Epidemiological and Simulation approaches. Based on the approaches identified, we propose a basic framework for evaluation and recommend the use of multiple approaches to evaluation to enable a comprehensive and contextualised description of outbreak detection performance.ConclusionThe varied nature of performance evaluation demonstrated in this review supports the need for further development of evaluation methods to improve comparability between studies. Our findings indicate that no single approach can fulfil all evaluation requirements. We propose that the cornerstone approaches to evaluation identified provide key contributions to support internal and external validity and comparability of study findings, and suggest these be incorporated into future recommendations for performance assessment.