Impaired lung function associates with deterioration of glycemic control and diabetes-related oxidative stress in long-standing type 2 diabetes. We hypothesized that recent-onset type 2 diabetes ...patients exhibit abnormal pulmonary function when compared to glucose-tolerant controls and that the frequencies of single-nucleotide polymorphisms (SNPs), known to associate with lung dysfunction, are different between both groups.
Type 2 diabetes patients with a known disease duration<1 year (n=34) had similar age, sex distribution and BMI as overweight controls (n=26). Lung function was assessed by spirometry comprising predicted forced vital capacity (FVC%), predicted forced expiratory volume in one second (FEV1%) and the FEV1/FVC ratio. Multivariable linear regressions were performed to investigate group differences, which were adjusted for potential confounders such as age, sex, BMI, height and smoking status. SNP genotyping was conducted using real-time polymerase chain reaction-based allelic discrimination.
Patients with type 2 diabetes had lower FEV1%, FEV1/FVC and VO
(all p<0.05). Among patients with type 2 diabetes, FEV1% correlated positively with VO
(r=0.40, p<0.05) and FEV1/FVC correlated negatively with HbA
(r=-0.49, p<0.01). Regression analyses across the whole cohort indicated that the group differences in FEV1/FVC can be explained by the confounding effect of HbA
. The frequencies of the SNPs rs1042713, rs1079572, rs11172113, rs12504628, rs1422795, rs1481345, rs2235910, rs2277027, rs2284746, rs4341, rs7068966, rs925284, rs993925 and rs3824658 did not differ between both groups.
Recent-onset type 2 diabetes patients exhibit reductions in features of pulmonary function, which might be at least in part resulting from glucotoxicity.
This study examined intra-individual variability in a large sample (n = 629) of individuals with a history of mild traumatic brain injury (mTBI) or TBI referred for neuropsychological evaluation. ...Variability was assessed using the overall test battery mean standard deviation (OTBM SD). We found a negative linear relation between OTBM and OTBM SD (r = -.672) in this sample with a history of neurologic pathology, indicating that the variability is inversely related to cognitive performance and contrary to what is observed in most normative data. Analyses revealed main effects for OTBM and OTBM SD across three TBI severity groups: loss of consciousness (LOC) <1 h, LOC 1 h-6 days, and LOC >6 days. These effects were found for both a valid performance group (no failed embedded validity measures; n = 504) and an invalid performance group (failed one or more embedded validity measures; n = 125). These findings support that cognitive intra-individual variability is increased uniquely by both neuropathology and suboptimal effort, there is a dose-response relationship between neuropathology and cognitive variability, and intra-individual variability may have utility as a clinical index of both.
Nine-hundred and four consecutive patients, including 80 neurological patients and 470 with head injuries, were given neuropsychological tests. All 43 test scores were converted to normative Z ...-scores and averaged, giving an Overall Test Battery Mean (OTBM). A variable measuring effort correlated 0.73 with the OTBM. The OTBM mean score was 1.20 SD lower in those who failed the Word Memory Test (WMT) than in those who passed the WMT. Sub-optimal effort suppressed the OTBM 4.5 times more than did moderate-severe brain injury. When only those making a good effort were included, patients with severe brain injuries and neurological diseases scored significantly lower than groups presumed to have no neurological impairment, but these group differences were not seen when all cases were analysed together. These data illustrate the importance of measuring and controlling for sub-optimal effort in individual neuropsychological evaluations, as well as in empirical research with similar groups of patients.
Bigler et al. (
2013
, The Clinical Neuropsychologist) contend that weak methodology and poor quality of the studies comprising our recent meta-analysis led us to miss detecting a subgroup of mild ...traumatic brain injury (mTBI) characterized by persisting symptomatic complaint and positive biomarkers for neurological damage. Our computation of non-significant Q, tau
2
, and I
2
statistics contradicts the existence of a subgroup of mTBI with poor outcome, or variation in effect size as a function of quality of research design. Consistent with this conclusion, the largest single contributor to our meta-analysis, Dikmen, Machamer, Winn, and Temkin (1995, Neuropsychology, 9, 80) yielded an effect size, -0.02, that was smaller than our overall effect size of -0.07 despite using the most liberal definition of mTBI: loss of consciousness less than 1 hour, with no exclusion of subjects who had positive CT scans. The evidence is weak for biomarkers of mTBI, such as diffusion tensor imaging and for demonstrable neuropathology in uncomplicated mTBI. Postconcussive symptoms, and reduced neuropsychological test scores are not specific to mTBI but can result from pre-existing psychosocial and psychiatric problems, expectancy effects and diagnosis threat. Moreover, neuropsychological impairment is seen in a variety of primary psychiatric disorders, which themselves are predictive of persistent complaints following mTBI. We urge use of prospective studies with orthopedic trauma controls in future investigations of mTBI to control for these confounding factors.
Objectives: To address (1) Whether there is empirical evidence for the contention of Nichols and Gass that the MMPI-2/MMPI-2-RF FBS/FBS-r Symptom Validity Scale is a measure of Litigation Response ...Syndrome (LRS), representing a credible set of responses and reactions of claimants to the experience of being in litigation, rather than a measure of non-credible symptom report, as the scale is typically used; and (2) to address their stated concerns about the validity of FBS/FBS-r meta-analytic results, and the risk of false positive elevations in persons with bona-fide medical conditions. Method: Review of published literature on the FBS/FBS-r, focusing in particular on associations between scores on this symptom validity test and scores on performance validity tests (PVTs), and FBS/FBS-r score elevations in patients with genuine neurologic, psychiatric and medical problems. Results: (1) several investigations show significant associations between FBS/FBS-r scores and PVTs measuring non-credible performance; (2) litigants who pass PVTs do not produce significant elevations on FBS/FBS-r; (3) non-litigating medical patients (bariatric surgery candidates, persons with sleep disorders, and patients with severe traumatic brain injury) who have multiple physical, emotional and cognitive symptoms do not produce significant elevations on FBS/FBS-r. Two meta-analytic studies show large effect sizes for FBS/FBS-r of similar magnitude. Conclusions: FBS/FBS-r measures non-credible symptom report rather than legitimate experience of litigation stress. Importantly, the absence of significant FBS/FBS-r elevations in litigants who pass PVTs demonstrating credible performance, directly contradicts the contention of Nichols and Gass that the scale measures LRS. These data, meta-analytic publications, and recent test use surveys support the admissibility of FBS/FBS-r under both Daubert and the older Frye criteria.
We reply to Nichols' (2017) critique of our commentary on the MMPI-2/MMPI-2-RF Symptom Validity Scale (FBS/FBS-r) as a measure of symptom exaggeration versus a measure of litigation response syndrome ...(LRS). Nichols claims that we misrepresented the thrust of the original paper he co-authored with Gass; namely, that they did not represent that the FBS/FBS-r were measures of LRS but rather, intended to convey that the FBS/RBS-r were indeterminate as to whether the scales measured LRS or measured symptom exaggeration. Our original commentary offered statistical support from published literature that (1) FBS/FBS-r were associated with performance validity test (PVT) failure, establishing the scales as measures of symptom exaggeration, and (2) persons in litigation who passed PVTs did not produce clinically significant elevations on the scales, contradicting that FBS/FBS-r were measures of LRS. In the present commentary, we draw a distinction between the psychometric data we present supporting the validity of FBS/FBS-r, and the conceptual, non-statistical arguments presented by Nichols, who does not refute our original empirically based conclusions.
This study examined the influence of performance on cognitive and psychological symptom validity tests on neuropsychological and psychological test performance in claimants evaluated in a ...medico-legal context (N = 301) with symptoms of PTSD. A second purpose of this study was to examine the influence of the severity of PTSD symptoms on cognitive test performance after excluding patients who failed to put forth adequate best effort and who exaggerated psychiatric symptoms. Patients were administered a battery of neuropsychological measures that were aggregated into a composite measure, the Cognitive-Test Battery Mean (C-TBM). Patients were also administered a battery of psychological tests that were aggregated into another composite measure, the Psychological-Test Battery Mean (P-TBM). We found that failure on cognitive symptom validity tests was associated with significantly poorer neuropsychological functioning, but there was not a significant effect on psychological symptoms. Conversely, failure on psychological symptom validity tests was associated with higher levels of psychopathology, but there was not a significant effect on cognitive ability. Finally, once patients were screened for adequate effort and genuine symptom reporting, the severity of PTSD symptoms did not appear to influence cognitive ability. This is the first study that assessed both types of symptom validity testing in PTSD claimants, which is important given that previous literature has demonstrated cognitive impairment in PTSD and that individuals with PTSD tend to claim cognitive impairment. Implications of these findings are discussed with regard to the existing literature and the relationship between these two types of symptom validity tests.
A Misleading Review of Response Bias Rohling, Martin L; Larrabee, Glenn J; Greiffenstein, Manfred F ...
Psychological bulletin,
07/2011, Letnik:
137, Številka:
4
Journal Article
Recenzirano
In the May 2010 issue of
Psychological Bulletin
, R. E. McGrath, M. Mitchell, B. H. Kim, and L. Hough published an article entitled "Evidence for Response Bias as a Source of Error Variance in ...Applied Assessment" (pp. 450-470). They argued that response bias indicators used in a variety of settings typically have insufficient data to support such use in everyday clinical practice. Furthermore, they claimed that despite 100 years of research into the use of response bias indicators, "a sufficient justification for their use... in applied settings remains elusive" (p. 450). We disagree with McGrath et al.'s conclusions. In fact, we assert that the relevant and voluminous literature that has addressed the issues of response bias substantiates validity of these indicators. In addition, we believe that response bias measures should be used in clinical and research settings on a regular basis. Finally, the empirical evidence for the use of response bias measures is strongest in clinical neuropsychology. We argue that McGrath et al.'s erroneous perspective on response bias measures is a result of 3 errors in their research methodology: (a) inclusion criteria for relevant studies that are too narrow; (b) errors in interpreting results of the empirical research they did include; (c) evidence of a confirmatory bias in selectively citing the literature, as evidence of moderation appears to have been overlooked. Finally, their acknowledging experts in the field who might have highlighted these errors prior to publication may have prevented critiques during the review process.
Two-alternative forced-choice procedures have been the most widely employed for detecting incomplete effort and exaggeration of cognitive impairment. However, it cannot be assumed that different ...symptom validity tests (SVTs) are of equal sensitivity. In this study, 519 claimants referred for disability or personal injury related assessments were administered three SVTs, one based on digit recognition (Computerized Assessment of Response Bias, CARB), one using pictorial stimuli (Test of Memory Malingering, TOMM) and one employing verbal recognition memory (Word Memory Test, WMT). More than twice as many people failed the WMT than TOMM. CARB failure rates were intermediate between those on the other two tests. Thus, tests of recognition memory using digits, pictorial stimuli or verbal stimuli, all of which are objectively extremely easy tasks, resulted in widely different failure rates. This suggests that, while these tests may be highly specific, they vary substantially in their sensitivity to response bias.
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