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Objective: the objectives of this study were: (i) to estimate the rate of discrepancy between participant single-item self-reports of good memory and poor performance on a list-learning task and (ii) to identify the factors including age, gender and health status that influence these discrepant classifications., Study Design and Settings: in total, 14,172 individuals, aged 45-85, were selected from the 2008-09 Canadian Community Health Survey on Healthy Aging. We examined the individual characteristics of participants with and without discrepancies between memory self-reports and performance with a generalised linear model, adjusting for potential covariates., Results: the mean age of respondents was 62.9 years with 56.7% being female, 53.8% having post-secondary graduation and 83% being born in Canada. Higher discrepant classification rates we observed for younger people (6.77 versus 3.65 for lowest and highest group), female (5.90 versus 3.68) and with higher education (6.17 versus 3.52). Discrepant classification rates adjusted with all covariates were higher for those without chronic diseases (5.37 [95% Confidence Interval (CI): 4.16, 6.90] versus 4.05 95% CI: 3.38, 4.86; P = 0.0127), those who did not drink alcohol (5.87 95% CI: 4.69, 7.32 versus 3.70 95% CI: 3.00, 4.55; P < 0.0001), lonely participants (5.45 95% CI: 4.20, 7.04 versus 3.99 95% CI: 3.36, 4.77; P = 0.0081) and bilingual participants (5.67 95% CI: 4.18, 7.64 versus 3.83 95% CI: 3.27, 4.50; P = 0.0102)., Conclusion: the findings of this study suggest that the self-reported memory and memory performance differ in a substantial proportion of the population. Therefore, relying on a self-reported memory status may not accurately capture those experiencing memory difficulties., (© The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Purpose of the Study: The Decisional Balance Scale (DBS) was developed to assess older adults' attitudes related to driving and includes both intrapersonal and interpersonal motivations for driving. This study examined the psychometric properties of the DBS ratings across 3 time points in a sample of 928 older drivers who participated in the Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive)., Design and Methods: Measurement invariance of the DBS was assessed longitudinally and across gender., Results: Confirmatory factor analyses revealed that a two-factor model (positive and negative attitudes) for both driving beliefs related to the self and other provided a good fit to the data at each time point. Measurement invariance was supported across time and gender. Significant associations between the DBS factor scores and other driving measures (e.g., perceived driving ability and self-regulatory driving practices) provided evidence of convergent validity., Implications: The DBS appears to be a robust instrument for measuring attitudes toward driving and is recommended for continued use in future research on driving behaviors with older adults., (© The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The lack of gold standard diagnostic criteria for cognitive impairment in the absence of dementia has resulted in variable nomenclature, case definitions, outcomes, risk factors, and prognostic utilities. Our objective was to elucidate the clinical correlates of conversion to dementia in a longitudinal population-based sample. Using data from the Canadian Study of Health and Aging, a machine learning algorithm was used to identify symptoms that best differentiated converting from nonconverting cognitively impaired not demented participants. Poor retrieval was the sole predictor of conversion to dementia over 5 years. This finding suggests that patients with impaired retrieval are at greater risk for progression to dementia at follow-up. Employing significant predictors as markers for ongoing monitoring and assessment, rather than as clinical markers of conversion, is recommended given the less than optimal specificity of the predictive algorithms.

In contrast to expectations, demographic corrections to reduce biases against those of advanced age or few years of education does not universally improve diagnostic classification accuracy. Age corrections may be particularly problematic because age is also a risk factor for a dementia diagnosis. We found that simulating increased risk for dementia based on demographic variables, such as age, reduced the overall classification accuracy for demographically corrected simulated scores relative to the raw, uncorrected test scores. In clinical data with a small magnitude of association between age and dementia diagnosis, we found equivalent overall classification accuracy for demographically corrected and raw test scores. Regardless of the overall classification accuracy results, cutoff comparisons (16th and 9th percentiles) in clinical and simulated data demonstrated that for the most part, the sensitivity of raw scores was higher than the sensitivity of demographically corrected scores, but the specificity of scores corrected with normative data was superior.

Knowledge of the virus-induced immune response is important in understanding the pathophysiology of respiratory virus infections. Data on the cellular immune response is still limited and based mainly on experimental studies. Natural colds may differ in their pathophysiology from experimentally induced ones. To evaluate the inflammatory cell responses in the upper respiratory tract during natural colds we counted the number of lymphocytes, mast cells and macrophages in the nasal mucosa. Nasal biopsies were taken from 22 adult volunteers during the acute (2-4 days of symptoms) and convalescent phases (day 21) of the cold, and the numbers of cells were counted with immunohistochemical methods. Viral aetiology was identified in 14 (64%) subjects by using viral isolation, antigen detection and rhino-polymerase chain reaction assays. The number of T lymphocytes was increased in the nasal epithelium and that of T and B lymphocytes and mast cells in the subepithelial layer in the acute phase compared to the convalescent phase. Intraepithelial T lymphocyte counts were significantly higher in the subjects who had a proven viral infection or a finding of pathogenic bacteria in the nasopharynx compared to the subjects without such findings (P = 0.005 and P = 0.04, respectively). Contrary to the earlier experimental studies, we found that viruses cause accumulation of T and B lymphocytes and mast cells during the first days of a symptomatic naturally acquired respiratory infection.

Although a number of scoring procedures for clock drawing have emerged in the literature, no systematic comparison of the psychometric properties of various approaches has yet been conducted on a large sample of persons over 64 years of age diagnosed with dementia or deemed cognitively intact. The present study examined the reliability and validity of five scoring approaches (Doyon, Bouchard, Morin, Bourgeois, & Cote, 1991; Shulman, Shedletsky, & Silver, 1986; Tuokko, Hadjistavropoulos, Miller, & Beattie, 1992; Watson, Arfken, & Birge, 1993; Wolf-Klein, Silverstone, Levy, Brod, & Breuer, 1989) among the 493 participants of the Canadian Study of Health and Aging who completed clock drawing and who had a final diagnosis assigned at the conclusion of a comprehensive clinical examination. Inter- and intra-rater reliabilities were highest for the Tuokko et al. method. The Tuokko and Shulman scoring procedures had the highest sensitivities and relatively low specificities. The Wolf-Klein procedure had relatively low sensitivities and high specificities. Estimated areas under receiver operating curves were relatively high for all scoring methods. However, the area under the curve for the Watson procedure was significantly lower than the other procedures. All claims to the utility of clock drawing for differentiating between normal persons over 64 years of age and those with dementia appear validated.

Various clock scoring procedures have been developed in recent years as dementia screening measures. The current longitudinal study was developed to assess the predictive validity of the Clock Test (Tuokko, Hadjistavropoulos, Miller, Horton, & Beattie, 1995). Within a sample of subjects who initially did not meet dementia criteria, Clock Test scores (drawing, setting, and reading) distinguished between those who later met criteria for dementia as compared to subjects who did not. When impaired performance was identified as falling below cut-off on two or more subtests of the Clock Test, sensitivity and specificity were found to be 91% and 95% relative to time two diagnosis. Clock errors among the current sample were compared against normal control subjects from the Canadian Study of Health and Aging (CSHA). These comparative analyses attest to the relative normality of the clinic sample at the time of their initial assessment.

We carried out a prospective case-control study to analyze the etiology of respiratory tract infections among children with and without acute otitis media (AOM). Of the 658 patients admitted to our hospital during the period concerned, 197 (29.9%) had AOM, and for each such child the next patient of the same age was chosen as a control. The total number of virologically positive samples was 99 (50.3%) among the patients with AOM vs. 93 (47.2%) among the controls. The only etiologic agent that was more common in the patients with AOM was respiratory syncytial virus, found in 31 cases vs. 15 controls (relative risk [2.27]; 95% confidence interval, 1.18-4.35; P < .02). Our results confirm earlier observations from uncontrolled studies regarding the fact that respiratory syncytial virus is especially liable to cause AOM. Since respiratory syncytial virus is causing predictable epidemics, this finding could be useful for the timing of efforts to prevent AOM in young infants.

Many elderly people are treated with medications or are subjected to diseases which can cause hypoglycemia. We conducted the following studies to assess whether alterations in counterregulatory hormone release, decreased awareness of warning symptoms or alterations in psychomotor performance might increase the susceptibility of the elderly to hypoglycemia. Healthy, nonobese young (n = 10, age < 30) and old (n = 9, age > 65) subjects underwent paired hyperinsulinaemic clamp studies (insulin infusion rate 60 mU/m2.min). In the control study, glucose was kept at 5.0 mmol/L for 5 h. In the hypoglycemic study, glucose was kept at 5 mmol/L for 1 h and was lowered in stepwise fashion to 4.4, 3.8, 3.3, and 2.8 mmol/L in each subsequent hour. Subjects were blinded as to which study they were undergoing. Counterregulatory hormones were measured and a hypoglycemic symptom checklist was administered every 15 min in each study. Neuropsychological tests were performed at regular intervals. The glucose threshold for release of counterregulatory hormones was defined as the glucose level at which the values during the hypoglycemic study first exceeded values during the control study by 2 SD. The glucose threshold for glucagon and epinephrine release was higher in the young (approximately 3.3 mmol/L) than the old (approximately 2.8 mmol/L) and the epinephrine responses to hypoglycemia were also greater in the young. The threshold for release of GH (approximately 3.3 mmol/L) and norepinephrine and cortisol (approximately 2.8 mmol/L) was similar in each age group, as was the magnitude of release of these hormones. Although the variance in symptoms scores was large, the elderly appeared to have reduced awareness of the autonomic but not neuroglycopenic symptoms of hypoglycemia. There was no difference between young and old in the effect of hypoglycemia on neuropsychologic tests. We conclude that healthy elderly people may have impaired release of glucagon and epinephrine in response to hypoglycemia and reduced awareness of the autonomic symptoms of hypoglycemia.