Composite indices: rank robustness, statistical association, and redundancy

This article evaluates the robustness of rankings obtained from composite indices that combine information from two or more components via a weighted sum. It examines the empirical prevalence of robust comparisons using the method proposed by Foster et al. (2010). Indices examined are the Human Development Index (HDI), the Index of Economic Freedom (IEF), and the Environmental Performance Index (EPI). Key theoretical results demonstrate links between the prevalence of robust comparisons, Kendall’s tau rank correlation coefficient, and statistical association across components. Implications for redundancy among index components are also examined.

The prevalence and recognition of major depression among low-level aged care residents with and without cognitive impairment

Previous research has demonstrated a high level of depression in nursing homes. The current study was designed to determine the prevalence of depression, using a structured diagnostic interview, among older people with and without mild-moderate cognitive impairment residing in low-level care facilities. The results demonstrated that, consistent with previous research in nursing homes, 16.9% of older people were diagnosed with major depressive disorder. Less than half of these cases had been detected or treated. Individuals with moderate cognitive impairment were more likely to be depressed, but cognitive impairment did not appear to act as a strong impediment to the detection of depression by general practitioners. A low awareness of their use of antidepressant medications was demonstrated among older people prescribed this treatment, including those with normal cognitive function. Reasons for the poor recognition of depression among older people are discussed.

Continence prevalence and management in an acute hospital

Learning Objective 1: describe the prevalence of incontinence within an Australian acute care hospital

Learning Objective 2: describe the current management practices for incontinence with regard to patients in an acute care hospital
Introduction: In 1998 the World Health Organisation recognised the international problem of incontinence. However, incontinence remains a major problem that affects more than 3.8 million Australians. Currently, there are no Australian guidelines governing the management of continence within the acute healthcare setting. Cabrini Health sought to identify the prevalence of incontinence in the acute inpatient setting and pilot a Continence Management Program to improve patient safety and patient outcomes.

Aim: The aim of this study was to determine the prevalence of and current management practices for incontinence with regard to Cabrini Health inpatients.

Method: The sample comprised 392 inpatients across three campuses of Cabrini Health (mean age= 68.3 years). Continence prevalence was assessed using a validated Continence Point Prevalence Tool.

Results: Urinary incontinence prevalence was 14%. The resulting overall faecal incontinence prevalence was 7.4%. There were 113 (52.3%) patients who were not incontinent and were using a continence product/device. Fifteen (25.9%) patients were incontinent and were not using any form of continence product/device. There were 43 (74.1%) patients who were incontinent and were using a continence product/device. For the large majority of patients, the admission notes contained documentation of their bladder and bowel function. Specifically, 46 (11.8%) patients had no form of admission documentation relating to bowel function and 45 (11.5%) patients had no form of admission documentation regarding to bladder function.

Conclusions: This study provided baseline continence prevalence for Cabrini Health. There is a need for evidence-based guidelines to support the management of incontinent patients. These interventions will assist staff to educate patients on appropriate choice of continence products and enable patients to maintain or regain continence. Thereby, leading to improved outcomes for patients and improved risk management.

Gender differences in the prevalence of impaired fasting glycaemia and impaired glucose tolerance in Mauritius. Does sex matter?

Objective: To examine gender differences in the characteristics and prevalence of various categories of glucose tolerance in a population study in Mauritius.

Research design and methods: In 1998, a community-based cross-sectional survey was conducted in Mauritius. Categories of glucose metabolism were determined in 5388 adults, with an oral glucose tolerance test given to those who did not have previously diagnosed diabetes (n = 4036). Other cardiovascular risk factors were assessed among those without known diabetes.

Results: For men and women the prevalence of diabetes (22.0 vs. 21.8%, respectively) and the prevalence of coexisting impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) (3.2 vs. 2.9%) were similar. However, men were twice as likely as women to have isolated IFG [5.1% (4.2–6.0) vs. 2.9% (2.3–3.5)], despite being younger, thinner and with lower plasma insulin but higher lipids. Conversely, the prevalence of isolated IGT was lower in men [9.0% (7.9–10.2) vs. 13.9% (12.6–15.1)]. Among non-diabetic individuals, fasting glucose was higher in men than women, whereas 2-h glucose was higher in women. In people without diabetes, women had significantly higher body mass index, beta cell function (HOMA-B), fasting and 2-h insulin than men and significantly lower waist-hip ratios, waist circumference, insulin sensitivity (HOMA-S) and triglycerides.

Conclusion: In Mauritius, the distribution of impaired glucose metabolism differs by sex. The observation that IFG is more prevalent in men and IGT more prevalent in women raises important questions about their underlying aetiology and the ability of the current glucose thresholds to equally identify men and women at high-risk of developing diabetes. IFG should be seen as a complimentary category of abnormal glucose tolerance, rather than a replacement for IGT.

Risk factors for female sexual dysfunction in the general population : exploring factors associated with low sexual function and sexual distress

Introduction. No previous population-based studies have used validated instruments to measure female sexual dysfunction (FSD) in Australian women across a broad age range.
Aim. To estimate prevalence and explore factors associated with the  components of FSD.
Main Outcome Measures. Sexual Function Questionnaire measured low sexual function. Female Sexual Distress Scale measured sexual distress.
Methods. Multivariate analysis of postal survey data from a random sample of 356 women aged 20–70 years.
Results. Low desire was more likely to occur in women in relationships for 20–29 years (odds ratio 3.7, 95% confidence intervals 1.1–12.8) and less likely in women reporting greater satisfaction with their partner as a lover (0.3, 0.1–0.9) or who placed greater importance on sex (0.1, 0.03–0.3). Low genital arousal was more likely among women who were perimenopausal (4.4, 1.2–15.7), postmenopausal (5.3, 1.6–17.7), or depressed (2.5, 1.1–5.3), and was less likely in women taking hormone therapy (0.2, 0.04–0.7), more educated (0.5, 0.3–0.96), in their 30s (0.2, 0.1–0.7) or 40s (0.2, 0.1–0.7), or placed greater importance on sex (0.2, 0.05–0.5). Low orgasmic function was less likely in women who were in their 30s (0.3, 0.1–0.8) or who placed greater importance on sex (0.3, 0.1–0.7). Sexual distress was positively associated with depression (3.1, 1.2–7.8) and was inversely associated with better communication of sexual needs (0.2, 0.05–0.5). Results were adjusted for other covariates including age, psychological, socioeconomic, physiological, and relationship factors.
Conclusions. Relationship factors were more important to low desire than age or menopause, whereas physiological and psychological factors were more important to low genital arousal and low orgasmic function than relationship factors. Sexual distress was associated with both psychological and relationship factors.

What is the "true" prevalence of female sexual dysfunctions and does the way we assess these conditions have an impact?

Introduction. A wide range of prevalence estimates of female sexual dysfunctions (FSD) have been reported.
Aim. Compare instruments used to assess FSD to determine if differences between instruments contribute to variation in reported prevalence.
Main Outcome Measures. Sexual Function Questionnaire combined with Female Sexual Distress Scale (SFQ-FSDS) was our gold standard, validated instrument for assessing FSD. Alternatives were SFQ alone and two sets of simple questions adapted from Laumann et al. 1994.
Methods. A postal survey was administered to a random sample of 356 Australian women aged 20 to 70 years.
Results. When assessed by SFQ-FSDS, prevalence estimates (95% confidence intervals) of hypoactive sexual desire disorder, sexual arousal disorder (lubrication), orgasmic disorder, and dyspareunia were 16% (12% to 20%), 7% (5% to 11%), 8% (6% to 12%), and 1% (0.5% to 3%), respectively. Prevalence estimates varied across alternative instruments for these disorders: 32% to 58%, 16% to 32%, 16% to 33%, and 3% to 23%, respectively. Compared with SFQ-FSDS alternative instruments produced higher estimates of desire, arousal and orgasm disorders and displayed a range of sensitivities (0.25 to 1.0), specificities (0.48 to 0.99), positive predictive values (0.01 to 0.56), and negative predictive values (0.95 to 1.0) across the disorders investigated. Kappa statistics comparing SFQ-FSDS and alternative instruments ranged from 0 to 0.71 but were predominantly 0.44 or less. Changing recall from previous month to 1 month or more in the previous year produced higher estimates for all disorders investigated. Including sexual distress produced lower estimates for desire, arousal, and orgasm disorders.
Conclusions. Prevalence estimates of FSD varied substantially across instruments. Relatively low positive predictive values and kappa statistics combined with a broad range of sensitivities and specificities indicated that different instruments identified different subgroups. Consequently, the instruments researchers choose when assessing FSD may affect prevalence estimates and risk factors they report.

The impact of study design on prevalence estimates of female sexual dysfunction

Introduction, objectives Despite increasing research, the true prevalence of Female Sexual Dysfunction (FSD) remains a contentious issue. Previous research suggests that aspects of study design affect the reported prevalence of FSD. We compare commonly used instruments for assessing FSD. Methods A random sample of 240 Australian women aged 20-70 participated in this population based, cross-sectional study. A questionnaire mailed to women across Australia included four instruments for assessing FSD. The Sexual Function Questionnaire combined with the Female Sexual Distress Scale (SFQ-FSDS) was employed as a standard, validated instrument. Alternative instruments were the SFQ alone and two modified versions of a set of questions originally developed by Laumann et al. Results When assessed by the SFQ-FSDS, prevalence estimates (and 95% confidence intervals) of Hypoactive Sexual Desire Disorder, Female Sexual Arousal Disorder (genital subtype), Female Orgasmic Disorder, and Dysparunia were 16%(11-20%), 8%(4-11%), 9%(6-13%), 2%(0.1-3%) respectively. The prevalence estimates of these same disorders obtained using alternative instruments were 32-55%, 17-35%, 17-33% and 3-25% respectively. The sensitivity of alternative instruments varied widely (0 to 1.0). Specificities ranged from 0.51 to 0.99. Positive predictive values ranged from 0 to 0.57. Negative predictive values were all above 0.90. Changing the time span for recalling sexual experiences in an instrument altered the prevalence estimates, sensitivity and specificity. 32% of women with low desire, 31% with low genital arousal, 36% with orgasm difficulty and 57% with sexual pain were sexually distressed. Conclusion Over a third of women who were classified as suffering FSD by alternative instruments did not have FSD when assessed by SFQ-FSDS. Alternative instruments produced substantially higher prevalence estimates of FSD and identified different groups of women. Consequently, the instruments researchers choose to assess FSD may affect both the prevalence estimates and risk factors they report.

Relationships between measures of fitness, physical activity, body composition and vascular function in children

Background : The prevalence of obesity and physical inactivity in Western countries has increased rapidly. Both are modifiable risk factors for cardiovascular disease. Atherosclerosis begins in childhood and endothelial dysfunction is its earliest detectable manifestation.

Methods : We assessed flow-mediated dilation (FMD) in 129 children (75 female; 10.3 + 0.3 yrs; 54 male; 10.4; 0.3 yrs). FMD was normalised for differences in the eliciting shear rate stimulus between subjects (SR_AUC). Fitness was assessed as peak oxygen uptake during an incremental treadmill exercise test (VO₂peak). Body composition was measured using a dual-energy X-ray absorptiometry (DEXA) scan. Physical activity (PA) was assessed using Actigraph accelerometers. The cohort was split into tertiles according to FMD% and also FMD% corrected for SR_AUC to gain insight into the determinants of vascular function.

Results : Across the cohort, significant correlations were observed between FMD%/SR_AUC and DEXA percentage fat (r = −0.23, p = 0.009) and percentage lean mass (r = 0.21, p = 0.008), and also with PA performed at moderate-to-high intensity (r = 0.363, p = 0.001). For children in the lowest FMD%/SR_AUC tertile, a stronger relationship with all PA measures was observed, particularly with high intensity PA (r = 0.572, P = 0.003). Regression analysis revealed that high intensity PA was the only predictor of impaired FMD%/SR_AUC.

Conclusions : These data suggest that traditional risk factors for CHD in adult populations impact upon vascular function in young people. Furthermore, it appears that individuals with impaired FMD may benefit from performing high intensity PA, whereas no relationships exist between FMD and lower intensities of PA or between PA and FMD in those subjects who possess preserved vascular function a priori.

Altered cardiac autonomic nervous function in depression

Background:
Depression is an independent risk factor for coronary artery disease. Autonomic instability may play a mediating or moderating role in this relationship; however this is not well understood. The objective of this study was to explore cardiac autonomic function and cardiac arrhythmia in depression, the correlation between depression severity and Heart Rate Variability (HRV) related indices, and the prevalence of arrhythmia.

Methods:
Individuals (n = 53) with major depression as assessed by the Diagnostic and Statistical Manual of Mental Disorders, who had a Hamilton Rating Scale for Depression (HAMD) score ≥20 and a Zung Self-Rating Depression Scale score > 53 were compared to 53 healthy individuals, matched for age and gender. Multichannel Electrocardiograph ECG-92C data were collected over 24 hours. Long-term changes in HRV were used to assess the following vagally mediated changes in autonomic tone, expressed as time domain indices: Standard deviation of the NN intervals (SDNN), standard deviation of 5 min averaged NN intervals (SDANN), Root Mean Square of the Successive Differences (RMSSD) and percentage of NN intervals > 50 ms different from preceding interval (pNN50). Pearson’s correlations were conducted to explore the strength of the association between depression severity (using the SDS and HRV related indices, specifically SDNN and low frequency domain / high frequency domain (LF/HF)).

Results:
The values of SDNN, SDANN, RMSSD, PNN50 and HF were lower in the depression group compared to the control group (P<.05). The mean value of the LF in the depression group was higher than the in control group (P<.05). Furthermore the ratio of LF/HF was higher among the depression group than the control group (P<.05). A linear relationship was shown to exist between the severity of the depression and HRV indices. In the depression group, the prevalence of arrhythmia was significantly higher than in the control group (P<.05), particularly supraventricular arrhythmias.

Conclusions:
Our findings suggest that depression is accompanied by dysfunction of the cardiac autonomic nervous system, and further, that depression severity is linked to severity of this dysfunction. Individuals with depression appear to be susceptible to premature atrial and/or ventricular disease.

Among vitamin B12 deficient older people, high folate levels are associated with worse cognitive function: combined data from three cohorts

Folate fortification of food aims to reduce the number of babies born with neural tube defects, but has been associated with cognitive impairment when vitamin B12 levels are deficient. Given the prevalence of low vitamin B12 levels among the elderly, and the global deployment of food fortification programs, investigation of the associations between cognitive impairment, vitamin B12, and folate are needed.

Similar prevalence of acetabular labral tear in professional ballet dancers and sporting participants

OBJECTIVE: To compare the prevalence of acetabular labral tear in male and female professional ballet dancers with age-matched and sex-matched sporting participants and to determine the relationship to clinical findings and cartilage defects. DESIGN: Case-control study. SETTING: Clinical and radiology practices. PARTICIPANTS: Forty-nine (98 hips) male and female professional ballet dancers (current and retired) with median age 30 years (range: 19-64 years) and 49 (98 hips) age-matched and sex-matched sporting participants. INDEPENDENT VARIABLES: Group (ballet or sports), sex, age, hip cartilage defects, history of hip pain, Hip and Groin Outcome Score, passive hip internal rotation (IR), and external rotation range of movement (ROM). MAIN OUTCOME MEASURES: Labral tear identified with 3T magnetic resonance imaging (MRI). RESULTS: Labral tears were identified in 51% of all 196 hips. The prevalence did not differ significantly between the ballet and sporting participants (P = 0.41) or between sexes (P = 0.34). Labral tear was not significantly associated with clinical measures, such as pain and function scores or rotation ROM (P > 0.01 for all). Pain provocation test using IR at 90° of hip flexion had excellent specificity [96%, 95% confidence intervals (CIs), 0.77%-0.998%] but poor sensitivity (50%, 95% CI, 0.26%-0.74%) for identifying labral tear in participants reporting hip pain. Older age and cartilage defect presence were independently associated with an increased risk of labral tear (both P < 0.001). CONCLUSIONS: The prevalence of labral tear in male and female professional ballet dancers was similar to a sporting population. Labral tears were not associated with clinical findings but were related to cartilage defects, independent of aging. CLINICAL RELEVANCE: Caution is required when interpreting MRI findings as labral tear may not be the source of the ballet dancer's symptoms.