Survey questions asking about taboo topics such as sexual activities, illegal behaviour such as social fraud, or unsocial attitudes such as racism, often generate inaccurate survey estimates which are distorted by social desirability bias. Due to self-presentation concerns, survey respondents underreport socially undesirable activities and overreport socially desirable ones. This article reviews theoretical explanations of socially motivated misreporting in sensitive surveys and provides an overview of the empirical evidence on the effectiveness of specific survey methods designed to encourage the respondents to answer more honestly. Besides psychological aspects, like a stable need for social approval and the preference for not getting involved into embarrassing social interactions, aspects of the survey design, the interviewer’s characteristics and the survey situation determine the occurrence and the degree of social desirability bias. The review shows that survey designers could generate more valid data by selecting appropriate data collection strategies that reduce respondents’ discomfort when answering to a sensitive question.

Determinants of social desirability bias in sensitive surveys: a literature review

Parkinson's Disease (PD) is a common neurodegenerative disorder. We sought to synthesize studies on the prevalence of PD to obtain an overall view of how the prevalence of this disease varies by age, by sex, and by geographic location. We searched MEDLINE and EMBASE for epidemiological studies of PD from 1985 to 2010. Data were analyzed by age group, geographic location, and sex. Geographic location was stratified by the following groups: 1) Asia, 2) Africa, 3) South America, and 4) Europe/North America/Australia. Meta-regression was used to determine whether a significant difference was present between groups. Forty-seven studies were included in the analysis. Meta-analysis of the worldwide data showed a rising prevalence of PD with age (all per 100,000): 41 in 40 to 49 years; 107 in 50 to 59 years; 173 in 55 to 64 years; 428 in 60 to 69 years; 425 in 65 to 74 years; 1087 in 70 to 79 years; and 1903 in older than age 80. A significant difference was seen in prevalence by geographic location only for individuals 70 to 79 years old, with a prevalence of 1,601 in individuals from North America, Europe, and Australia, compared with 646 in individuals from Asia (P < 0.05). A significant difference in prevalence by sex was found only for individuals 50 to 59 years old, with a prevalence of 41 in females and 134 in males (P < 0.05). PD prevalence increases steadily with age. Some differences in prevalence by geographic location and sex can be detected. © 2014 International Parkinson and Movement Disorder Society

The prevalence of Parkinson's disease: A systematic review and meta‐analysis

Objective: To quantify the risk of developing dementia in those with mild cognitive impairment (MCI).

Method:  Meta-analysis of inception cohort studies.

Results:  Forty-one robust cohort studies were identified. To avoid heterogeneity clinical studies, population studies and clinical trials were analysed separately. Using Mayo defined MCI at baseline and adjusting for sample size, the cumulative proportion who progressed to dementia, to Alzheimer’s disease (AD) and to vascular dementia (VaD) was 39.2%, 33.6% and 6.2%, respectively in specialist settings and 21.9%, 28.9% and 5.2%, respectively in population studies. The adjusted annual conversion rate (ACR) from Mayo defined MCI to dementia, AD and VaD was 9.6%, 8.1% and 1.9%, respectively in specialist clinical settings and 4.9%, 6.8% and 1.6% in community studies. Figures from non-Mayo defined MCI and clinical trials are also reported.

Conclusion:  The ACR is approximately 5–10% and most people with MCI will not progress to dementia even after 10 years of follow-up.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0447.2008.01326.x

Rate of progression of mild cognitive impairment to dementia – meta-analysis of 41 robust inception cohort studies

In the past 10 years, there has been a virtual explosion in the literature concerning the construct of mild cognitive impairment. The interest in this topic demonstrates the increasing emphasis on the identification of the earliest features of cognitive disorders such as Alzheimer disease and other dementias. Mild cognitive impairment represents the earliest clinical features of these conditions and, hence, has become a focus of clinical, epidemiologic, neuroimaging, biomarker, neuropathological, disease mechanism, and clinical trials research. This review summarizes the progress that has been made while also recognizing the challenges that remain.

https://jamanetwork.com/journals/jamaneurology/articlepdf/798590/nnr90016_1447_1455.pdf

Mild cognitive impairment: ten years later.

The construct of mild cognitive impairment (MCI) has evolved over the past 10 years since the publication of the new MCI definition at the Key Symposium in 2003, but the core criteria have remained unchanged. The construct has been extensively used worldwide, both in clinical and in research settings, to define the grey area between intact cognitive functioning and clinical dementia. A rich set of data regarding occurrence, risk factors and progression of MCI has been generated. Discrepancies between studies can be mostly explained by differences in the operationalization of the criteria, differences in the setting where the criteria have been applied, selection of subjects and length of follow-up in longitudinal studies. Major controversial issues that remain to be further explored are algorithmic versus clinical classification, reliability of clinical judgment, temporal changes in cognitive performances and predictivity of putative biomarkers. Some suggestions to further develop the MCI construct include the tailoring of the clinical criteria to specific populations and to specific contexts. The addition of biomarkers to the clinical phenotypes is promising but requires deeper investigation. Translation of findings from the specialty clinic to the population setting, although challenging, will enhance uniformity of outcomes. More longitudinal population-based studies on cognitive ageing and MCI need to be performed to clarify all these issues.

/pdf/mild-cognitive-impairment-a-concept-in-evolution-1w0llqhx7k.pdf

Mild cognitive impairment: A concept in evolution

Asymptotic optimality of double sampling plans employing generalized regression estimators

Following the pioneering work of Singh and Grewal [19] we examine how their inverse approach of revising Warner’s [22] and Kuk’s [8] techniques of directly eliciting a randomized response to unbiasedly estimate a finite population proportion bearing a stigmatizing feature, fares as a viable competitor We consider sampling by general schemes admitting positive inclusion probabilities for single and paired persons facilitating estimation Our live-data based numerical presentations suggest Singh and Grewal’s [19] approach as quite promising

Generating randomized response by inverse mechanism

A test for Weibull populations

A well-known estimator for the shape parameter of a two-parameter Weibull distribution from a failure-censored sample involves a preliminary test of aa null hypothesis concerning the parameter. Efficiency of the resulting testimator varies with the chosen level of significance of the test. We present an alternative procedure with a higher efficiency over this for each significance level under various circumstances. Appropriate choice of significance level is also discussed.

On testimating the weibull shape parameter

Results on necessary and sufficient conditions for non-negativity of variance estimators are briefly reviewed. Some new sufficient conditions are also given.

Arijit Chaudhuri

Papers

Asymptotic optimality of double sampling plans employing generalized regression estimators

Generating randomized response by inverse mechanism

A test for Weibull populations

On testimating the weibull shape parameter

Non-negative unbiased variance estimators