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Background: Mild cognitive impairment (MCI) is at least as prevalent as dementia after transient ischaemic attack (TIA)/stroke and is increasingly recognised as an important outcome in observational studies and randomised trials. However, there is no consensus on how impairment should be defined, and numerous different criteria exist. Previous studies have shown that different criteria for cognitive impairment impact on prevalence rates in epidemiological studies. However, there are few data on how operational differences within established criteria (e.g. Petersen-MCI) affect measured impairment rates and the performance of short cognitive tests such as the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), particularly in cerebrovascular disease. We therefore evaluated the effect of different operational definitions on measured rates of Petersen-MCI and on reliability of short cognitive tests in patients with TIA and stroke. Methods: Consecutive patients underwent the MMSE, MoCA and neuropsychological battery ≥1 year after TIA or stroke in a population-based study. MCI was defined using the Petersen method and subclassified as single or multiple domain, both with (original) and without (modified) subjective memory impairment. Different cut-offs (>1, >1.5 and >2 standard deviations, SD) on a given test relative to published norms were compared together with use of single versus multiple tests to define domain impairment. Results: 91 non-demented subjects completed neuropsychological testing (mean age ± SD 69.7 ± 11.6 years, 54 male, 49 stroke) at a mean of 3.1 ± 1.9 years after the index event. Rates of cognitive impairment ranged from 14/91 (15%) for MCI-original at >2 SD cut-off to 61/91 (67%) MCI-modified at >1 SD cut-off, and the proportion of MCI that was multiple domain varied, e.g. 24/46 (52%) versus only 5/27 (20%) at 1 versus 2 SD cut-off for MCI-modified. Requirement for subjective memory complaint approximately halved estimates [e.g. 17 (19%) vs. 39 (43%) for MCI at 1.5 SD cut-off, single test definition], whereas use of multiple tests versus a single test to define a cognitive domain had less impact. In general, diagnostic accuracy was higher, and optimal cut-offs lower, on MMSE and MoCA for multiple-domain versus single-domain MCI, but the MoCA appeared superior for detecting MCI-modified, whereas the MMSE performed well in detecting MCI-original. Conclusion: Even within established criteria for MCI, differences in operational methodology result in 4-fold variation in MCI estimates. Optimal MMSE and MoCA cut-offs are lower, and reliability more similar, when criteria for MCI are more stringent. Our findings have implications for sample size and adjusted relative risk calculations in randomised trials and for comparisons between studies. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The prolonged length of stay (PLOS) score has recently been derived and validated in 2 independent national cohorts of acute stroke patients in Israel. The present study aimed to determine the performance of the PLOS score in an independent population-based cohort of stroke patients in a health care system considerably different from that in which the score was derived. Methods: The study was performed on all 434 patients with ischemic stroke or intracerebral hemorrhage hospitalized during the first 5 years of the population-based Oxford Vascular Study (OXVASC) in Oxfordshire, UK. Median (interquartile range) length of stay (LOS) and rates of LOS ≥7 days and LOS ≥30 days by the PLOS score were calculated. Model discrimination was assessed by the c-statistic and goodness of fit was evaluated with the Hosmer-Lemeshow test. Results: Median LOS and rates of LOS ≥7 days increased with the increase in PLOS score among all inpatients and hospital survivors. In the analysis of LOS ≥7 days, the PLOS c-statistic (95% CI) was 0.676 (0.618-0.734) for all inpatients and 0.722 (0.664-0.779) for hospital survivors. Findings were similar for LOS ≥30 days. The Hosmer-Lemeshow showed good calibration. Conclusions: The PLOS score successfully predicted PLOS in the OXVASC population of acute stroke patients. Although the score was originally derived for the prediction of prolonged acute hospitalization, it successfully predicted prolonged total LOS. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]