Health service utilization in IBD: comparison of self-report and administrative data

<p>Abstract</p> <p>Background</p> <p>The reliability of self-report regarding health care utilization in inflammatory bowel disease (IBD) is unknown. If proven reliable, it could help justify self-report as a means of determining health care utilization and associated costs.</p> <p>Methods</p> <p>The Manitoba IBD Cohort Study is a population-based longitudinal study of participants diagnosed within 7 years of enrollment. Health care utilization was assessed through standardized interview. Participants (n = 352) reported the total number of nights hospitalized, frequency of physician contacts in the prior 12 months and whether the medical contacts were for IBD-related reasons or not. Reports of recent antibiotic use were also recorded. Actual utilization was drawn from the administrative database of Manitoba Health, the single comprehensive provincial health insurer.</p> <p>Results</p> <p>According to the administrative data, 15% of respondents had an overnight hospitalization, while 10% had an IBD-related hospitalization. Self-report concordance was highly sensitive (92%; 82%) and specific (96%; 97%, respectively). 97% of participants had contact with a physician in the previous year, and 69% had IBD-related visits. Physician visits were significantly under-reported and there was a trend to over-report the number of nights in hospital.</p> <p>Conclusions</p> <p>Self-report data can be helpful in evaluating health service utilization, provided that the researcher is aware of the systematic sources of bias. Outpatient visits are well identified by self-report. The discordance for the type of outpatient visit may be either a weakness of self-report or a flaw in diagnosis coding of the administrative data. If administrative data are not available, self-report information may be a cost-effective alternative, particularly for hospitalizations.</p

Reverse genetic studies of mitochondrial DNA-based diseases using a mouse model

In the situation that it would not be able to produce model animals for mitochondrial diseases caused by mitochondrial DNA (mtDNA) with pathogenic mutations, we succeeded in generating mice with pathogenic deletion mutant mtDNA (ΔmtDNA), named “mito-mice”, by direct introduction of mitochondria with ΔmtDNA into mouse zygotes. In the mito-mice, accumulation of ΔmtDNA induced mitochondrial respiration defects in various tissues, resulting in mitochondrial disease phenotypes, such as low body weight, lactic acidosis, ischemia, myopathy, heart block, deafness, male infertility, and renal failure. Thus, mito-mice are the first model animal for mtDNA-based diseases, and the mice could be valuable for understanding precise pathogeneses and testing therapies of mitochondrial diseases. In the present review, we summarized reverse genetic studies using the mito-mice

Segregation of functional networks is associated with cognitive resilience in Alzheimer's disease

Cognitive resilience is an important modulating factor of cognitive decline in Alzheimer's disease, but the functional brain mechanisms that support cognitive resilience remain elusive. Given previous findings in normal aging, we tested the hypothesis that higher segregation of the brain's connectome into distinct functional networks represents a functional mechanism underlying cognitive resilience in Alzheimer's disease. Using resting-state functional MRI, we assessed both resting-state-fMRI global system segregation, i.e. the balance of between-network to within-network connectivity, and the alternate index of modularity Q as predictors of cognitive resilience. We performed all analyses in two independent samples for validation: First, we included 108 individuals with autosomal dominantly inherited Alzheimer's disease and 71 non-carrier controls. Second, we included 156 amyloid-PET positive subjects across the spectrum of sporadic Alzheimer's disease as well as 184 amyloid-negative controls. In the autosomal dominant Alzheimer's disease sample, disease severity was assessed by estimated years from symptom onset. In the sporadic Alzheimer's sample, disease stage was assessed by temporal-lobe tau-PET (i.e. composite across Braak stage I & III regions). In both samples, we tested whether the effect of disease severity on cognition was attenuated at higher levels of functional network segregation. For autosomal dominant Alzheimer's disease, we found higher fMRI-assessed system segregation to be associated with an attenuated effect of estimated years from symptom onset on global cognition (p = 0.007). Similarly, for sporadic Alzheimer's disease patients, higher fMRI-assessed system segregation was associated with less decrement in global cognition (p = 0.001) and episodic memory (p = 0.004) per unit increase of temporal lobe tau-PET. Confirmatory analyses using the alternate index of modularity Q revealed consistent results. In conclusion, higher segregation of functional connections into distinct large-scale networks supports cognitive resilience in Alzheimer's disease

Glomerular filtration rate and prevalence of chronic kidney disease in Wilms’ tumour survivors

Glomerular filtration rate (GFR) was evaluated in 32 Wilms’ tumour survivors (WTs) in a cross-sectional study using 99 Tc-diethylene triamine pentaacetic acid (99 Tc-DTPA) clearance, the Schwartz formula, the new Schwartz equation for chronic kidney disease (CKD), cystatin C serum concentration and the Filler formula. Kidney damage was established by beta-2-microglobulin (B-2-M) and albumin urine excretion, urine sediment and ultrasound examination. Blood pressure was measured. No differences were found between the mean GFR in 99 Tc-DTPA and the new Schwartz equation for CKD (91.8 ± 11.3 vs. 94.3 ± 10.2 ml/min/1.73 m2 [p = 0.55] respectively). No differences were observed between estimated glomerular filtration rate (eGFR) using the Schwartz formula and the Filler formula either (122.3 ± 19.9 vs. 129.8 ± 23.9 ml/min/1.73 m2 [p = 0.28] respectively). Increased urine albumin and B-2-M excretion, which are signs of kidney damage, were found in 7 (22%) and 3 (9.4%) WTs respectively. Ultrasound signs of kidney damage were found in 14 patients (43%). Five patients (15.6%) had more than one sign of kidney damage. Eighteen individuals (56.25%) had CKD stage I (10 with signs of kidney damage; 8 without). Fourteen individuals (43.75%) had CKD stage II (6 with signs of kidney damage; 8 without). The new Schwartz equation for CKD better estimated GFR in comparison to the Schwartz formula and the Filler formula. Furthermore, the WT survivors had signs of kidney damage despite the fact that GFR was not decreased below 90 ml/min/1.73 m2 with 99 Tc- DTPA

White matter hyperintensities are higher among early‐onset Alzheimer's disease participants than their cognitively normal and early‐onset nonAD peers: Longitudinal Early‐onset Alzheimer's Disease Study (LEADS)

IntroductionWe compared white matter hyperintensities (WMHs) in early-onset Alzheimer's disease (EOAD) with cognitively normal (CN) and early-onset amyloid-negative cognitively impaired (EOnonAD) groups in the Longitudinal Early-Onset Alzheimer's Disease Study.MethodsWe investigated the role of increased WMH in cognition and amyloid and tau burden. We compared WMH burden of 205 EOAD, 68 EOnonAD, and 89 CN participants in lobar regions using t-tests and analyses of covariance. Linear regression analyses were used to investigate the association between WMH and cognitive impairment and that between amyloid and tau burden.ResultsEOAD showed greater WMHs compared with CN and EOnonAD participants across all regions with no significant differences between CN and EOnonAD groups. Greater WMHs were associated with worse cognition. Tau burden was positively associated with WMH burden in the EOAD group.DiscussionEOAD consistently showed higher WMH volumes. Overall, greater WMHs were associated with worse cognition and higher tau burden in EOAD.HighlightsThis study represents a comprehensive characterization of WMHs in sporadic EOAD. WMH volumes are associated with tau burden from positron emission tomography (PET) in EOAD, suggesting WMHs are correlated with increasing burden of AD. Greater WMH volumes are associated with worse performance on global cognitive tests. EOAD participants have higher WMH volumes compared with CN and early-onset amyloid-negative cognitively impaired (EOnonAD) groups across all brain regions