Removal Of Participants Research Articles

Schizotypy 17 years on: Prediction of schizotypic individual differences in midlife.

The picture for the long-term prediction of schizotypic individual difference features in relation to schizotypy assessed earlier in life remains opaque. Whereas schizotypy assessed earlier in life, typically during the late teen years, has been shown to predict nonaffective psychotic illness as well as the presence of nonaffective psychotic features (Chapman et al., 1994; Lenzenweger, 2021), the presence in midlife (mid-30s) of nonpsychotic schizotypic features in those assessed for schizotypy earlier in life remains to be demonstrated. The current study, which reports on a 17-year follow-up study, addresses this void in the schizotypy literature. Seventeen years after an initial psychometric assessment for schizotypy, in a sample of emerging adults (age = 18) with no prior history of psychotic illness, Perceptual Aberration Scale scores predicted elevated schizotypal personality features, increased schizophrenia-related personality disorder features (particularly schizotypal and paranoid), and elevated schizophrenia proneness scores at age 35. This pattern of associations was maintained even after the removal of participants with a diagnosis of nonaffective psychosis. The associations also remained largely unchanged net of state anxiety levels at initial and later assessments. These results support the emergence or maintenance of schizotypic psychopathology features consistent with a model that views schizotypy as the underlying liability for schizotypic psychopathology phenotypes. The results also provide additional support for both the construct validity of the initial psychometric schizotypy measure (Perceptual Aberration Scale) as well as the validity of the psychometric high-risk paradigm. Longitudinal research remains an illuminating and informative approach to understanding the nature of schizophrenia-related psychopathology by utilizing time as an essential scientific lever. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Errors and repetitions on tests of language, verbal learning, and memory in cognitively unimpaired adults at increased risk for Alzheimer’s disease

AbstractBackgroundErrors and repetitions on verbal fluency and list learning tasks have been found to predict progression to MCI and differentiate between healthy aging, MCI, and dementia. This study examined whether errors and/or repetitions on verbal measures were cross‐sectionally associated with amyloid pathology in baseline cognitively unimpaired (CU) adults, and provided additional information beyond traditional total score measures.MethodWe included 437 participants from the Wisconsin Registry for Alzheimer’s Prevention who completed comprehensive neuropsychological testing and amyloid (Ab) positron emission tomography (PET) scans using Pittsburgh Compound‐B (PiB). Ab(+/‐) status was determined using an established threshold average distribution volume ratio(DVR) >1.19 across several brain regions. From the most recent testing visit, we extracted the total number of errors and repetitions from the Rey Auditory Verbal‐Learning Test (AVLT), animal fluency, and letter fluency; these were summed to form error and repetitions composites. We ran ANCOVAs with Ab(+/‐) as predictor; age, sex, and WRAT‐3 reading were covariates. Cohen’s D effect sizes characterized strength of relationships, where higher errors = negative effect sizes, and higher total scores = positive effect sizes. Sensitivity analyses examined errors and total scores from individual tests, and removal of participants who progressed to MCI.ResultSample characteristics are presented in Table1. Relationships between error, repetition and total score variables are shown in Figure1. Ab(+/‐) was a significant predictor of the error composite (p = .001) but not the repetition composite. Ab(+/‐) was significantly associated with AVLT learning total (p = .01), but not with animal or letter fluency totals. Secondary analyses revealed that AVLT errors alone were associated with Ab(+/‐) (p<.0001); effect sizes were greatest for AVLT errors (d = ‐.46) than for the error composite (d = ‐.39) or for AVLT total score (d = .39) (Figure 2). Removal of impaired participants yielded similar effect sizes.ConclusionFindings from this CU sample suggest that AVLT errors may be more sensitive to early AD pathology than traditional total score measures. Errors on list‐learning may represent other cognitive and/or sensory processes (e.g., auditory processing, hearing, attention, inhibition) that are sensitive to AD but are not represented in total scores. Future research includes examining longitudinal and additional error composites’ relationships with AD pathology to develop more sensitive cognitive measures.

Drinking and smoking polygenic risk is associated with childhood and early-adulthood psychiatric and behavioral traits independently of substance use and psychiatric genetic risk

Alcohol drinking and tobacco smoking are hazardous behaviors associated with a wide range of adverse health outcomes. In this study, we explored the association of polygenic risk scores (PRS) related to drinks per week, age of smoking initiation, smoking initiation, cigarettes per day, and smoking cessation with 433 psychiatric and behavioral traits in 4498 children and young adults (aged 8–21) of European ancestry from the Philadelphia neurodevelopmental cohort. After applying a false discovery rate multiple testing correction accounting for the number of PRS and traits tested, we identified 36 associations related to psychotic symptoms, emotion and age recognition social competencies, verbal reasoning, anxiety-related traits, parents’ education, and substance use. These associations were independent of the genetic correlations among the alcohol-drinking and tobacco-smoking traits and those with cognitive performance, educational attainment, risk-taking behaviors, and psychopathology. The removal of participants endorsing substance use did not affect the associations of each PRS with psychiatric and behavioral traits identified as significant in the discovery analyses. Gene-ontology enrichment analyses identified several neurobiological processes underlying mechanisms of the PRS associations we report. In conclusion, we provide novel insights into the genetic overlap of smoking and drinking behaviors in children and young adults, highlighting their independence from psychopathology and substance use.

Challenges for Women with Disabilities Accessing Reproductive Health Care Around the World: A Scoping Review

This scoping review provides an overview of access to reproductive health care for women with physical disabilities in low-middle income and high-income countries from 1995 to 2017. The paper reviews 40 qualitative studies, identified by searching 10 databases including Ovid (Health and psychosocial instruments, NHS economic evaluation database), OVID MEDLINE, Pubmed, Informit (Health and Society, Health collection, Humanities and social sciences collection), ProQuest Central (ProQuest XML), CINAHL Plus (EBSCO), ScienceDirect Journal, Wiley Online Library, Google Scholar, BioMed Central. Nine main themes were identified. They included: unavailable, unreliable or dated health information; removal of participants’ autonomy; limited reproduction-related education; health provider-derived barriers; systemic barriers to access; socio-economic barriers; transportation barriers; Family-related barriers; and reproductive technology barriers. These themes are explored across various country contexts, including high-income countries with high access to reproductive health care, high-income countries with low access, low-middle income countries with high access, and low-middle income countries with low access. Some suggestions for improvements are also outlined.

Evaluative conditioning affects the subsequent acquisition of differential fear conditioning as indexed by electrodermal responding and stimulus evaluations.

It is currently unclear whether the acquisition of negative stimulus valence in evaluative and fear conditioning paradigms is interrelated or independent. The present study used a transfer paradigm to address this question. Three groups of participants were trained in a picture-picture evaluative conditioning paradigm before completing acquisition of differential fear conditioning using graphical shapes as conditional stimuli (CSs). In group congruent, the shape used as CS+ (paired with the US during fear conditioning) was paired with negative pictures, whereas the shape used as CS- (presented alone during fear conditioning) was paired with positive pictures. In group incongruent, the shape used as CS+ was paired with positive pictures, whereas the shape used as CS- was paired with negative pictures. In group different, different shapes were employed in evaluative and fear conditioning. Acquisition of differential electrodermal responses emerged within fewer acquisition trials in groups congruent and different than in group incongruent. Transfer of evaluative learning across paradigms was evident only after removal of participants who failed to display evaluative conditioning. The current research indicates that stimulus valence acquired during evaluative conditioning transfers to fear conditioning and will differentially affect the acquisition of fear learning as indexed by subjective evaluations and electrodermal responses. The findings suggest that evaluative and fear conditioning are not independent.

Peripapillary retinal nerve fiber layer thickness and cognitive function across the adult lifespan in the Rhineland study

Introduction Decreasing retinal nerve fiber layer thickness (RNFL) has been associated with an increased risk of developing cognitive impairment in older adults. This may indicate that the integrity of retinal axons partially parallels that of the central nervous system. However, it is not clear from previous research whether RNFL thickness is associated with cognitive performance in cognitively normal adults. In this cross-sectional study, we used spectral-domain optical coherence tomography (SD-OCT) and detailed cognitive evaluations to determine the degree to which peripapillary RNFL (pRNFL) thickness is associated with cognition across the adult lifespan in a large community-based sample. Methods The data used for this investigation were obtained from 1306 participants of the on-going longitudinal Rhineland Study (age range = 30–95 years). During participants’ first visit, pRNFL thickness was measured using SD-OCT and neuropsychological assessments were completed as part of a larger battery. Cognitive performance was assessed in executive function, working memory, episodic memory and crystallized intelligence. Z-scores were calculated for continuous variables. We used linear regression analysis to quantify the strength of the relationships between pRNFL and cognitive test scores, expressed as difference in Z-score per SD increase in pRNFL. We performed three analyses: unadjusted; adjusted for age; adjusted for age, hypertension, refraction and visual acuity. Sensitivity analyses were conducted to determine whether the presence of cataracts or glaucoma influenced results. Results Participants with missing pRNFL (n = 50) or covariate (n = 47) data were excluded, leaving preliminary results available for 1209 participants, who had a mean age of 56 years (SD = 14 years) and comprised more women than men (56%). Overall, mean thickness of pRNFL was 99.91 μm (SD = 11.06 μm), and each additional year of participant age was associated with a thinning in pRNFL of 0.18 μm (95% CI = 0.13–0.23). In unadjusted models, thicker pRNFL was associated with better performance in executive functioning (0.15 SD, 95% CI = 0.09–0.21) and episodic memory (0.13 SD, 95% CI = 0.06–0.17), with worse performance in crystallized intelligence (0.08 SD, 95% CI = 0.02–0.14) and was not associated with working memory performance (0.03 SD, 95% CI = −0.02 to 0.09). These small effects largely disappeared upon adjustment for age and were no longer statistically significant (episodic memory: 0.04 SD, 95% CI = −0.01 to 0.10; crystallized intelligence: −0.04 SD, 95% CI = −0.10 to 0.02), except for the association of pRNFL and executive function (0.06 SD, 95% CI = 0.00–0.12). Further adjustment for hypertension, refraction and visual acuity did not change this latter relationship (0.07 SD, 95% CI = 0.01–0.12). The removal of participants with prevalent cataracts or a diagnosis of glaucoma did not affect the point estimate of the association of pRNFL with executive function, yet the 95% CI widened due to the smaller sample size (0.07 SD, 95% CI = −0.01 to 0.12; n reduction = 145). Conclusion In this exploratory investigation, we observed that pRNFL thickness was not associated with cognitive performance after adjustment for age, aside from a small association with executive function.

APOL1 Nephropathy Risk Variants and Incident Cardiovascular Disease Events in Community-Dwelling Black Adults.

APOL1 renal risk variants are strongly associated with chronic kidney disease in Black adults, but reported associations with cardiovascular disease (CVD) have been conflicting. We examined associations of APOL1 with incident coronary heart disease (n=323), ischemic stroke (n=331), and the composite CVD outcome (n=500) in 10 605 Black participants of the REGARDS study (Reasons for Geographic and Racial Differences in Stroke). Primary analyses compared individuals with APOL1 high-risk genotypes to APOL1 low-risk genotypes in Cox proportional hazards models adjusted for CVD risk factors and African ancestry. APOL1 high-risk participants were younger and more likely to have albuminuria at baseline than APOL1 low-risk participants. The risk of incident stroke, coronary heart disease, or composite CVD end point did not significantly differ by APOL1 genotype status in multivariable models. The association of APOL1 genotype with incident composite CVD differed by diabetes mellitus status (Pinteraction=0.004). In those without diabetes mellitus, APOL1 high-risk genotypes associated with greater risk of incident composite CVD (hazard ratio, 1.67; 95% confidence interval, 1.12-2.47) compared with those with APOL1 low-risk genotypes in multivariable adjusted models. This latter association was driven by ischemic strokes (hazard ratio, 2.32; 95% confidence interval, 1.33-4.07), in particular, those related to small vessel disease (hazard ratio, 5.10; 95% confidence interval, 1.55-16.56). There was no statistically significant association of APOL1 genotypes with incident CVD in subjects with diabetes mellitus. The APOL1 high-risk genotype was associated with higher stroke risk in individuals without but not those with chronic kidney disease in fully adjusted models. APOL1 high-risk status is associated with CVD events in community-dwelling Black adults without diabetes mellitus.

The Systematic Removal of Participants Post-Randomization Can Lead to Alternate Explanations of the Results

The strength of randomized controlled trials is that they allow causal statements to be made about the efficacy of an intervention. This is because the randomization of participants to experimental condition distributes participants with different characteristics to each experimental condition by chance, including variations in the outcome variables of interest. Such randomization allows the use of statistical tests incorporating probability statements regarding the chance that the difference observed between conditions is due to chance (eg, 1 in 20 chance; P<.05). Any systematic removal of participants post-randomization interferes with the assumption of the randomness of participant allocation to experimental condition. This can introduce a potential confound or alternative explanation of the results. The recently published study by Rooke et al [1] removed participants from the analysis who reported other treatment use during the study (n=5). The removal of participants was done post-randomization and in a systematic fashion (ie, anyone who reported using other treatment was not included in the analysis). All participants who reported receiving other treatment were in the control condition and were allocated to receive the Web address of an education only website. Even if some participants in the intervention condition had also accessed other treatment, this would still be a systematic, post-randomization removal of participants. However, it is easier to develop alternate explanations of the findings of this trial because all participants using other treatment were from the control condition. From one perspective, it is possible that the excluded participants were those who were experiencing the most serious problems with their Cannabis use. If this is the case, it could make it less likely that significant differences would be observed between experimental condition by reducing the variance between participants. Alternatively, perhaps these were the five participants in the control condition who were the most motivated to reduce their Cannabis use. This could mean that participants in the control condition were less motivated, on average, than those in the intervention condition, to do something about their Cannabis use. This could serve as an alternate explanation of the findings in this study. Given that only five participants were removed out of 225 (or 230 if control and intervention group participant totals are added?) randomized at baseline, it is quite possible that this alternate explanation is untrue. However, the authors do expose themselves to alternate explanations of the findings by the removal of these participants. If the systematic removal of participants post-randomization is deemed necessary, one possible solution would be to run (and report on) the analysis with and without these participants included. Such sensitivity analyses would go a long way towards addressing any possible confounds that may have been introduced.

Recreational Cycling and Cardiorespiratory Fitness in English Youth

Schoolchildren who cycle to school have higher cardiorespiratory fitness (CRF) than those who are driven or use public transport. The purpose of this study was to determine whether recreational cycling is similarly associated with CRF. Participants were 5578 (54% males) English schoolchildren (10.0-15.9 yr). All reported frequency of recreational cycling events via 7-d recall. Responses were categorized as follows: "noncyclists" = 0, "occasional cyclists" = 1-4, or "regular cyclists" = 5+ (times per week). CRF was assessed using the 20-m shuttle run test with performance classified as "fit" or "unfit" based on FITNESSGRAM standards. Overall, 26% of males and 46% of females were noncyclists. Compared with noncyclists, the 40% of males and 42% of females classified as occasional cyclists were more likely to be fit (males: odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.07-1.59; females: OR = 1.41, 95% CI = 1.13-1.76). Regular cyclists (34% males and 12% females) had a greater likelihood still of being classified as fit (males: OR = 1.58, 95% CI = 1.29-1.95; females: OR = 1.55, 95% CI = 1.09-2.20). No odds remained significant after adjusting for physical activity. Removal of participants who cycled to school had little overall effect on the likelihood of being classified as being fit. Previous research has focused only on young people's commuter cycling habits, at the expense of the more common activity of recreational cycling. Recreational cycling may provide an alternative target for interventions to increase physical activity and improve CRF youth. Recreational cycling could potentially serve as a way to gain cycling confidence and establish habits that act as precursors to commuter cycling.