Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods

 Background: Efficient and reliable surveillance and notification systems are vital for monitoring public health and disease outbreaks. However, most surveillance and notification systems are affected by a degree of underestimation (UE) and therefore uncertainty surrounds the 'true' incidence of disease affecting morbidity and mortality rates. Surveillance systems fail to capture cases at two distinct levels of the surveillance pyramid: from the community since not all cases seek healthcare (under-ascertainment), and at the healthcare-level, representing a failure to adequately report symptomatic cases that have sought medical advice (underreporting). There are several methods to estimate the extent of under-ascertainment and underreporting. Methods. Within the context of the ECDC-funded Burden of Communicable Diseases in Europe (BCoDE)-project, an extensive literature review was conducted to identify studies that estimate ascertainment or reporting rates for salmonellosis and campylobacteriosis in European Union Member States (MS) plus European Free Trade Area (EFTA) countries Iceland, Norway and Switzerland and four other OECD countries (USA, Canada, Australia and Japan). Multiplication factors (MFs), a measure of the magnitude of underestimation, were taken directly from the literature or derived (where the proportion of underestimated, under-ascertained, or underreported cases was known) and compared for the two pathogens. Results: MFs varied between and within diseases and countries, representing a need to carefully select the most appropriate MFs and methods for calculating them. The most appropriate MFs are often disease-, country-, age-, and sex-specific. Conclusions: When routine data are used to make decisions on resource allocation or to estimate epidemiological parameters in populations, it becomes important to understand when, where and to what extent these data represent the true picture of disease, and in some instances (such as priority setting) it is necessary to adjust for underestimation. MFs can be used to adjust notification and surveillance data to provide more realistic estimates of incidence. © 2014 Gibbons et al.; licensee BioMed Central Ltd.

Measuring human well-being in Thailand : a normative social choice approach

Numerous methods exist within the literature to measure human well-being. A limitation of some approaches however is that they fail to explicitly consider society's views, choices and preferences on how human well-being should be defined. It is possible though to explicitly incorporate society's value judgements in defining and measuring human well-being through normative social choice theory. Normative social choice theory reflects the views, opinions and perspectives of societies of differing economic and social circumstances so that measures of human well-being retain their relevance for public policy makers in those countries. This paper reviews two indicators based on this theory for Thailand over the 25 year period, 1975-1999. The first indicator focuses on certain hierarchical needs and the second is a measure of adjusted national income. It is concluded that both measures provide important insights.

Measuring regional sustainability: lessons to be learned

Developing tools for measuring progress toward sustainability has proven a challenging task. Indicators offer an excellent means to explore the success or otherwise of management strategies. They also allow reporting social, economic and environmental aspects of sustainability. To ensure that the tools developed are effective in measuring the progress toward sustainable futures, an evaluation of the methods and the indicators used must be undertaken so that with progress there is learning and with the new knowledge methods can be redesigned to better advance sustainability. This paper discusses a study carried out in the south west region of Victoria, Australia, using indicators as the basis for developing a tool to measure progress toward sustainability. By evaluating the methods and indicators used in the study this paper provides an insight into the challenges encountered and the lessons learned. Issues explored include selecting indicators, collating data, integrating social, economic and environmental aspects of sustainability and using an adaptive approach.

Measuring the impact of intimate partner violence on the health of women in Victoria, Australia

Objective: Using burden of disease methodology, estimate the health risks of intimate partner violence (IPV) among women in Victoria, Australia.

Methods: We calculated population attribute fractions (from survey data on the prevalence of IPV and the relative risks of associated health problems in Australia) and determined health outcomes by applying them to disability-adjusted life year estimates for the relevant disease and injury categories for Victoria, Australia for 2001.

Findings: For women of all ages IPV accounted for 2.9% (95% uncertainty interval 2.4-3.4%)  of the total disease and injury burden.  Among women 18-44 years of age, IPV was associated with 7.9% (95% uncertainty interval 6.4-935%) of the overall disease burden and was a larger risk to health than risk factors traditionally included in burden of disease studies, such as raised blood pressure, tobacco use and increased body weight.  Poor mental health contributed 73% and substance abuse 22% to the disease burden attributed to IPV.

Conclusion: Our findings suggest that IPV constitutes a significant risk to women's health.  Mental health policy-makers and health workers treating common mental health problems need to be aware that IPV is an important factor.  Future research should concentrate on evaluating effective interventions to prevent women being exposed to violence, and identifying the most appropriate mental health care for victims to reduce short- and long-term disability

A psychometric evaluation of the Gudjonsson Suggestibility Scales : problems associated with measuring suggestibility as a difference score composite

The current paper provides a detailed examination of the psychometric properties of the Gudjonsson Suggestibility Scales (Gudjonsson, 1997) which have been widely used to measure individual suggestibility. Several fundamental problems associated with the Shift and Total Suggestibility subscales are identified and discussed. Two arguably more conceptually coherent methods of scoring the Shift subscale (‘Shift-positive’ and ‘Shift-negative’) are introduced. A confirmatory factor analytic model based on two oblique factors and relative answering regression effects between corresponding items was tested and supported based on a sample of 220 children. Based on a latent variable estimation approach, the internal consistency reliabilities associated with the Shift subscale scores were found to be unacceptably low. Consequently, we propose that until the problems associated with Shift-standard and Total Suggestibility is addressed successfully, use of the GSS should be limited to the Yield subscale.

Measuring quality of life in alcohol and other drug users - the need for improvement

Objective : The use of Quality of Life (QoL) -related measures in Alcohol and Other Drug-related research has increased dramatically over the past decade. However, there remains a great deal of confusion about which type of QoL measure is most valid, what each constrict actually measures and the ethicality of the process of QoL measurement and its subsequent transfer to monetary value. This is particularly important in regard to subsequent resource allocation on the basis of Quality Adjusted Life Years (QALYs). We aim to review the logic of current QoL -related measurement and determine the most conceptually valid way of measuring QoL.

Methods : This review considers some of the broad principles that concern quality of life assessment. These are discussed in relation to health-related quality of life (HRQoL) and the measurement of subjective well-being.

Results : We argue that there are serious logical and methodological issues concerning HRQoL measurement, to the extent that the instruments may not be regarded as valid measures of life quality as this term is generally understood.

Conclusions : It is recommended that HRQoL measurement be abandoned in favour of three separate forms of measurement as medical symptoms, subjective well-being and specific dimensions of psychological ill-being.

Minimising total survey error when measuring entrepreneurship in Tonga

This study illustrates how the Total Survey Error (TSE) paradigm can identify and help reduce multiple sources of error inherent in survey work in the developing world. Of particular concern are mode errors and coverage errors caused by the 'theoretical teledensity threshold' of doing phone surveys in developing countries. The study outlines ways to improve response rate and to avoid interviewer and measurement error. It narrates the sampling design and its limitations as well as some of the qualitative aspects of total survey quality such as, translation, ethics and budgeting. The final section discusses implications for further research in statistical auto-correlation and data gathering using PDAs.

The suitability of polycystic ovary syndrome-specific questionnaires for measuring the impact of PCOS on quality of life in clinical trials

Objectives: Generic patient-reported outcome (PRO) measures underestimate the impact of polycystic ovary syndrome (PCOS) on quality of life (QoL). The aim of this review was to identify PCOS-specific QoL measures and establish whether their development history and measurement properties support their use in clinical trials.

Methods: A systematic search was conducted using terms synonymous with “PCOS” and “QoL.” Following identification of measures, further searches were undertaken using the questionnaire name and abbreviation to explore its use, development history, and demonstrated measurement properties.

Results: Of 56 abstracts screened, 21 reported using PRO measures. One PCOS-specific QoL measure was identified: the PolyCystic Ovary Syndrome Questionnaire (PCOSQ). Nine papers show that the PCOSQ’s development history is somewhat incomplete, and that it does not have good content validity. The PCOSQ subscales demonstrate acceptable levels of reliability (0.70–0.97) and partial known-groups validity as well as convergent/divergent validity with other PRO instruments. Responsiveness
to change is variable and minimally important differences have not been established.

Conclusions: The PCOSQ is the only condition-specific measure of the impact of PCOS on QoL. Additional research is required to ensure its comprehensiveness, sensitivity, and to guide interpretation prior to including in clinical trials.

The health-related quality of life of overweight and obese adolescents - a study measuring body mass index and adolescent-reported perceptions

Objective. To determine whether the health-related quality of life (HRQOL) of overweight and obese adolescents is significantly lower than that of their healthy weight counterparts, and if so, whether any demographic trends exist and the relative contribution of each HRQOL dimension.

Methods. Cross-sectional analysis of 2,890 students participating in the Pacific Obesity Prevention in Communities Project, Australia. HRQOL was measured using the Pediatric Quality of Life Inventory (PedsQL) adolescent module. Adolescent height and weight were measured by trained field workers and weight categories assigned according to the International Obesity Task Force BMI cut-off points for adolescents. Multivariate linear regression analyses were undertaken to estimate the mean differences in HRQOL scores between (i) overweight and healthy weight, and (ii) obese and healthy weight adolescents, whilst adjusting for gender, age and socioeconomic status quartile.

Results. The sample had a mean age of 14.6 years (range 11–18), 56.2% boys, 20.2% overweight and 6.3% obese. Higher weight status categories were associated with lower HRQOL scores (mean PedsQL scores: healthy weight: 79.1, overweight: 77.7 and obese: 73.7). Relative to the healthy weight group, and after adjustments, overweight and obese adolescents reported 1.44 (p = 0.005) and 5.55 (p < 0.001) lower HRQOL summary scores, respectively. Overweight adolescents reported significantly lower scores in physical and social functioning, whilst obese adolescents reported significantly lower scores in the same dimensions plus emotional functioning. Girls and younger (< 15 years) adolescents reported greater mean negative HRQOL differences associated with excess weight.

Conclusions. Overweight and obesity in adolescents are associated with significantly lower HRQOL scores.

Measuring core inflation in Bangladesh : an unobserved components approach

This paper attempts to construct a core inflation measure for Bangladesh using an Unobserved Components modelling approach. One advantage of the Unobserved Components approach is that this method satisfies some essential statistical criteria for a core inflation measure, which are not guaranteed to be met in other traditional exclusionbased methods. The estimated core inflation series performs well in tracking headline inflation and picking the major turning points in actual inflation. It is also found that there is a negative covariance between the shocks to the core inflation and cyclical inflation, indicating that there may be positive correlation between demand and supply shocks in Bangladesh.

The Australian burden of disease study : measuring the loss of health from diseases, injuries and risk factors

This is an overview of the first burden of disease and injury studies carried out in Australia. Methods developed for the World Bank and World Health Organization Global Burden of Disease Study were adapted and applied to Australian population health data. Depression was found to be the top- ranking cause of non-fatal disease burden in Australia, causing 8% of the total years lost due to disability in 1996. Mental disorders overall were responsible for nearly 30% of the non-fatal disease burden. The leading causes of total disease burden (disability-adjusted life years [DALYs]) were ischaemic heart disease and stroke, together causing nearly 18% of the total disease burden. Depression was the fourth leading cause of disease burden, accounting for 3.7% of the total burden. Of the 10 major risk factors to which the disease burden can be attributed, tobacco smoking causes an estimated 10% of the total disease burden in Australia, followed by physical inactivity (7%).