Effects of the COVID-19 Pandemic on Patients with Concussion Presenting to a Specialty Clinic.

The purpose of this study is to examine the effects of the COVID-19 pandemic on patients presenting with concussion at a specialty clinic. This study used a retrospective cohort design to compare participants (n = 3021) with a suspected concussion, including a Pandemic cohort (n = 1139; March 2020-February 2021) and a Pre-Pandemic cohort (n = 1882; March 2019-February 2020). Concussions and patient characteristics including age, sex, days since injury, and injury mechanism were extracted from an electronic health record. There were 39.5% (n = 743) fewer concussions in Pandemic. Pandemic presented to the clinic 25.8 days later (p < 0.001) and were 1.9 years older (p < 0.001) than Pre-Pandemic. Sport-related concussions decreased 59.6% overall for Pandemic. Pandemic was associated with proportional increases of concussions involving recreational activities (odds ratio [OR] = 6.11; p < 0.001), motor vehicle collisions (OR = 1.39; p < 0.001), and falls/assaults (OR = 1.33; p < 0.001). A total of 9.4% (107/1139) of all Pandemic concussion initial clinical visits were performed using telehealth (0% in Pre-Pandemic). Concussion visit volume to a sub-specialty clinic decreased by approximately 40% during the COVID-19 pandemic and patients presented to the clinic nearly 1 month later. The increase in telehealth highlights the potential to expand clinical care outreach during the current and future pandemics or similar restrictive time periods.

Cross-Sectional Examination of Homocysteine Levels with Sarcopenia and Its Components in Memory Clinic Outpatients.

BACKGROUND: Homocysteine is a common risk factor for cognitive impairment and sarcopenia. However, very few studies have shown an association between sarcopenia and serum homocysteine levels after adjustment for cognitive function. OBJECTIVE: The purpose of this study was to investigate the relationship between homocysteine and sarcopenia in memory clinic patients. METHODS: This cross-sectional study investigated outpatients in a memory clinic. We enrolled 1,774 participants (≥65 years old) with measured skeletal muscle mass index (SMI), hand grip strength (HGS), and homocysteine. All participants had undergone cognitive assessments and were diagnosed with dementia, mild cognitive impairment, or normal cognition. Patient characteristics were compared according to sarcopenia presence, SMI level, or HGS. Multivariate logistic regression analysis was performed to determine the association of homocysteine with sarcopenia, low SMI, or low HGS. Next, linear regression analysis was performed using HGS as a continuous variable. RESULTS: Logistic regression analysis showed that low HGS was significantly associated with homocysteine levels (p = 0.002), but sarcopenia and low SMI were not. In linear regression analysis, HGS was negatively associated with homocysteine levels after adjustment for Mini-Mental State Examination score (ß= -2.790, p < 0.001) or clinical diagnosis of dementia (ß= -3.145, p < 0.001). These results were similar for men and women. CONCLUSION: Our results showed a negative association between homocysteine and HGS after adjustment for cognitive function. Our findings strengthen the assumed association between homocysteine and HGS. Further research is needed to determine whether lower homocysteine levels lead to prevent muscle weakness.

Neuropsychiatric Symptoms in Patients with Dementia Associated with Increased Psychological Distress in Caregivers During the COVID-19 Pandemic.

BACKGROUND: The social isolation imposed by COVID-19 pandemic can have a major impact on the mental health of dementia patients and their caregivers. OBJECTIVE: We aim to evaluate the neurological decline of patients with dementia and the caregivers' burden during the pandemic. METHODS: We performed a cross-sectional study. Caregivers of dementia patients following in the outpatient clinic were included. A structured telephone interview composed of the Neuropsychiatric Inventory Questionnaire (NPI-Q), Zarit Burden Interview (ZBI), Beck Depression (BDI) and Anxiety (BAI) Inventories to address cognitive, behavioral, and functional changes associated with social distancing during the Sars-Cov-2 outbreak. Patients were divided in two groups according to caregivers' report: with perceived Altered Cognition (AC) and Stable Cognition (SC). RESULTS: A total of 58 patients (median age: 57 years [21-87], 58.6%females) and caregivers (median age: 76.5 years [55-89], 79.3%females) were included. Cognitive decline was shown by most patients (53.4%), as well as behavioral symptoms (48.3%), especially apathy/depression (24.1%), and functional decline (34.5%). The AC group (n = 31) presented increased behavioral (67.7%versus 25.9%, p = 0.002) and functional (61.3%versus 3.7%, p < 0.001) changes when compared to the SC group. In the AC group, ZBI, BDI, NPI-Q caregiver distress, and NPI-Q patient's severity of symptoms scores were worse than the SC group (p < 0.005 for all). CONCLUSION: Patients' neuropsychiatric worsening and caregiver burden were frequent during the pandemic. Worsening of cognition was associated with increased caregivers' psychological distress.

Increased stress, weight gain and less exercise in relation to glycemic control in people with type 1 and type 2 diabetes during the COVID-19 pandemic.

INTRODUCTION: Lockdown measures have a profound effect on many aspects of daily life relevant for diabetes self-management. We assessed whether lockdown measures, in the context of the COVID-19 pandemic, differentially affect perceived stress, body weight, exercise and related this to glycemic control in people with type 1 and type 2 diabetes. RESEARCH DESIGN AND METHODS: We performed a short-term observational cohort study at the Leiden University Medical Center. People with type 1 and type 2 diabetes ≥18 years were eligible to participate. Participants filled out online questionnaires, sent in blood for hemoglobin A1c (HbA1c) analysis and shared data of their flash or continuous glucose sensors. HbA1c during the lockdown was compared with the last known HbA1c before the lockdown. RESULTS: In total, 435 people were included (type 1 diabetes n=280, type 2 diabetes n=155). An increase in perceived stress and anxiety, weight gain and less exercise was observed in both groups. There was improvement in glycemic control in the group with the highest HbA1c tertile (type 1 diabetes: -0.39% (-4.3 mmol/mol) (p<0.0001 and type 2 diabetes: -0.62% (-6.8 mmol/mol) (p=0.0036). Perceived stress was associated with difficulty with glycemic control (p<0.0001). CONCLUSIONS: An increase in perceived stress and anxiety, weight gain and less exercise but no deterioration of glycemic control occurs in both people with relatively well-controlled type 1 and type 2 diabetes during short-term lockdown measures. As perceived stress showed to be associated with glycemic control, this provides opportunities for healthcare professionals to put more emphasis on psychological aspects during diabetes care consultations.

Impact of clinical pharmacy in oncology and hematology centers: A systematic review.

BACKGROUND: Oncology and hematology is a complex and specific area that requires monitoring by a multidisciplinary team capable of personalizing the treatment of each patient. Clinical pharmacy services have the potential to contribute significantly to the effective and economical care of cancer patients. OBJECTIVE: To evaluate, synthesize and critically present the available evidence on the impact of the Clinical Pharmacy in the treatment of patients with hematological cancer. METHOD: A review was carried out on the bases PubMed/MEDLINE, LILACS and Google Scholar. The included studies were: studies that evaluated the effects of pharmaceutical interventions in clinical in oncology and hematology services and having as a population patient with hematological cancer. RESULTS: 17 studies were selected among 745 identified. 4.771 patients were included, with an average follow-up time of 15.3 months. Patients affected by some type of hematological cancer, undergoing chemotherapy treatment, showed better adherence and continuity when accompanied by a clinical pharmacist, added to this professional in carrying out interventions, provides control of symptoms such as cancer pain, nausea and constipation and, thus, contributes to decrease the length of hospital stay. CONCLUSION: The implementation of a Clinical Pharmacy service in oncology and hematology centers contributes significantly to the effectiveness of pharmacotherapeutic treatment, treatment costs reduction, safety increase in the use of medications and the patient's quality of life.

Pediatric Neurosurgery After the COVID-19 Pandemic: Management Strategies from a Single Pediatric Hospital in Italy.

BACKGROUND: Coronavirus disease-2019 (COVID-19) pandemic had a great impact over all elective neurosurgical activity and important implications in management of neurosurgical urgencies. During the pandemic, some pediatric hospitals reported their experiences. After the emergency phase of the COVID-19 pandemic, the health care system needs to be reorganized to again manage all nonurgent activities, while ensuring safety of both patients and health care workers. METHODS: We developed preventive measures to limit any possibility of COVID-19 spread, according to the principles of epidemiologic prevention and suggestions from recent literature. To evaluate the efficacy of these measures, we retrospectively reviewed the neurosurgical activity at our institution from May 4 to July 15, 2020. RESULTS: One hundred nineteen patients were admitted to the neurosurgical ward, and 80 surgical procedures were performed. Furthermore, 130 outpatient clinics were scheduled. A total of 258 nasopharyngeal swabs and 249 specific interviews were performed. In our series, no cases of positivity for severe acute respiratory syndrome coronavirus-2 infection were found, and no surgical cases were postponed. DISCUSSION: We present the management of the neurosurgical activity after the emergency phase at the Neurosurgical Department of Giannina Gaslini Children's Hospital in Genoa, Italy. CONCLUSIONS: The Italian health care system is undertaking a process of reorganization of resources, in an attempt to restore all nonurgent activities while ensuring safety. After the emergency phase, we are learning to live together with COVID-19 and, although epidemiologic data are encouraging, we must be prepared for an eventual second peak.

The experience of Hamad General Hospital collaborative anticoagulation clinic in Qatar during the COVID-19 pandemic.

Hamad General Hospital Anticoagulation Clinic is one of the largest collaborative-practice clinics of its type in Qatar. The patients being followed at this clinic are typically complex and vulnerable. During the coronavirus disease 2019 pandemic, measures were implemented at the clinic to minimize the exposure of patients and healthcare providers to the acute respiratory syndrome coronavirus-2 and to promote social distancing. These measures included extending INR-recall period, transitioning to direct oral anticoagulant drugs whenever feasible, home visits to elderly and immunocompromised patients for INR testing, establishing an anticoagulation hotline, and relocation of warfarin dispensing from the main pharmacy to the anticoagulation clinic. In addition, the clinic shifted its multidisciplinary team meetings onto an online platform using Microsoft Teams. Telehealth consultations were extensively utilized to closely follow up with the patients and ensure that anticoagulation efficacy and safety remained optimal. The aim of this paper is to share our experience and describe the measures adopted by the clinic as part of the Hamad Medical Corporation response to the emerging situation.

Apolipoprotein ɛ4 Affects Multiple Domains of Neuropsychological Functioning in a Sample of Elderly Hispanics.

Apolipoprotein ɛ4 allele (APOEɛ4) is the strongest genetic risk factor for sporadic Alzheimer's disease (AD), but inconsistencies have arisen in studies with Hispanics. The objective of this study was to explore APOEɛ4 expression and cognitive function in a sample of Panamanian older adults, including healthy controls, mild cognitive impairment, and AD. Participants with at least one copy of APOEɛ4 had a significantly lower performance in global cognition, verbal memory, executive functions, visuospatial abilities, regardless of diagnosis. The present study contributes to the understanding of the association of APOEɛ4 and impairment in specific cognitive domains in elderly Hispanics.

Relative changes in the pattern of diseases presenting in dermatology outpatient clinic in the era of the COVID-19 pandemic.

As an increasing number of COVID-19 cases, there were changes in the number of patients who attended the dermatology outpatient clinics. We aimed to investigate the change profiles of dermatologic diseases in the first and second months of the COVID-19 pandemic in Turkey by comparing with the corresponding period of the previous year. The total number and diagnosis of patients, who attended a tertiary care hospital for the dermatology outpatient clinic between 1 April 2020 and 31 May 2020, were included in this study. These data were compared with the corresponding period of the previous year. The percentage of the patients with scabies, contact dermatitis, psoriasis, pityriasis rosea, urticaria, and alopecia areata were statistically significantly increased a month after the occurrence of the COVID-19 pandemic, while the percentage of patients with scabies, alopecia areata, telogen effluvium, acne vulgaris, and xerosis cutis were statistically significantly increased 2 months after the occurrence of the COVID-19 pandemic (P < 0.05). An increase in the number of certain diseases such as urticaria and pityriasis rosea may indicate the risk of asymptomatic COVID-19 carriage in these patients. Polymerase chain reaction (PCR) and/or antibody-based further studies should be performed to explore whether certain dermatologic diseases are related to asymptomatic COVID-19 cases.

The psychological impact on an orthopaedic outpatient setting in the early phase of the COVID-19 pandemic: a cross-sectional study.

BACKGROUND: World Health Organization declared coronavirus disease-19 (COVID-19) a global pandemic on 11 March 2020, after the coronavirus claimed 4628 lives worldwide. Mental health challenges such as making impossible decisions and working under extreme pressures are expected to be faced by frontline healthcare workers who are directly involved in the care of COVID-19 patients. However, we question if significant stress levels might also be observed in a subspecialty musculoskeletal outpatient department, where staff are not first-line care providers of COVID-19 patients. We hypothesize that these healthcare workers also face significant psychological strain, and we aim to objectively determine the prevalence using a validated caregiver strain index. METHODS: A cross-sectional study was conducted in outpatient musculoskeletal clinics in a tertiary hospital in Singapore. We collected basic demographic data and used a 13-question tool adapted from the validated Caregiver Strain Index (CSI) to measure psychological strain in these healthcare workers. Participants were divided into 2 groups depending on the level of strain experienced. RESULTS: A total of 62 healthcare workers volunteered for this study. There were 32 participants (51.6%) who had 7 or more positive responses (group 1) and the remaining 30 participants (48.4%) were allocated to group 2. There were no significant differences between the two groups in terms of demographic data. "Work adjustments" (74.2%), "changes in personal plans" (72.6%), and finding it "confining" (72.6%) garnered the most positive responses in the questionnaire. On the other hand, "financial concerns" garnered the least positive responses (21.0%). CONCLUSION: The protracted duration of the COVID-19 outbreak and its resultant prolonged adjustments can have unintended consequences of wearing down healthcare resources otherwise allocated to chronic and elective conditions. Countries should ensure that measures are put in place to safeguard the mental well-being of our healthcare workers to avoid needing another reactive strategy in this battle against COVID-19.

The most common pediatric and adult dermatology patient complaints in a month of the COVID-19 pandemic in Turkey.

Severe acute respiratory syndrome coronavirus 2 is the coronavirus strain that causes coronavirus disease 2019 (COVID-19). The World Health Organization (WHO) has designated the ongoing COVID-19 outbreak a Public Health Emergency of International Concern. WHO declared COVID-19 as a pandemic on 11 March 2020. During the pandemic and lockdown period, many dermatologic clinics were temporarily closed in Turkey as well as all over the world. Taking the necessary precautions, the hospital continued to examine all emergent and elective patients who applied to our dermatology clinic. We investigated the most common reasons for admission of pediatric and adult patients who were admitted to our outpatient clinic between 30 March and 30 April 2020, the period with the highest number of COVID-19 patients in Turkey. In children and adult age groups, the most common reason for admission was acne (N: 10 [16.4%] and N: 89 [20.9%], respectively). Of the 99 acne patients, 70 (70.7%) were using systemic isotretinoin and applied to our clinic to repeat the prescription or continue the agent. The number of pediatric patients admitted to the dermatology department drastically reduced during the lockdown period, which was attributed to the curfew for children in the country.

Effectiveness of pharmacist intervention model for chronic kidney disease patients; a prospective comparative study.

Background Chronic Kidney Disease (CKD) is a global health concern with profound risk of cardiovascular disease, end stage renal failure and early mortality. Pharmacists' interventions during chronic disease management have been promising. However, evidence of pharmacist`s involvement in chronic kidney dosease is limited, particularly in developing countries. Objective To implement and evaluate the impact of pharmacist led intervention among pre-dialysis CKD patients. Setting Nephrology outpatient department of tertiary healthcare hospital. Methods Patients with chronic kidney disease from stage 2 to 4 attending hospital between October to December 2018 were enrolled in a multi-arm pre-post prospective study. Pharmacist interventional model consisted of disease education, dietary recommendations, counseling to improve medication adherence along with telephonic follow-up. Interventional group received pharmacist interventional model; whereas control group only received the usual care. The impact of pharmacist`s involvements were evaluated by observing the improvements in knowledge and adherence scores, physiological profile and body composition analysis assessed by body composition monitor (BF-508®) at the end of follow-up of 3 months. Both intervention and control groups were compared by appropriate statistical techniques. Main outcome measure Knowledge and adherence scores, physiological profile and body composition analysis Results Total 120 patients (60 in each group) completed the study. Baseline variables were comparable between the two groups. Pharmacist interventional model causes significant improvement in knowledge score upon follow up between intervention and control groups (19.10 ± 3.65 versus 17.57 ± 3.55, p = 0.022). Likewise, Medication adherence score of intervention group significantly improved as compared to control group (p < 0.05) following the implementation of pharmacist intervention model. Physiological analysis showed small improvements in the intervention group but were not significant. Body composition analysis revealed higher body and visceral fat in both groups at the end of follow up. Conclusion Our analysis underscored that the tested pharmacist interventional model is an effective tool in improving disease knowledge and medication adherence among patients with chronic kideney disease.

Obtaining and Modeling Variability in Travel Times From Off-Site Satellite Clinics to Hospitals and Surgery Centers for Surgeons and Proceduralists Seeing Office Patients in the Morning and Performing a To-Follow List of Cases in the Afternoon.

BACKGROUND: Hospitals achieve growth in surgical caseload primarily from the additive contribution of many surgeons with low caseloads. Such surgeons often see clinic patients in the morning then travel to a facility to do 1 or 2 scheduled afternoon cases. Uncertainty in travel time is a factor that might need to be considered when scheduling the cases of to-follow surgeons. However, this has not been studied. We evaluated variability in travel times within a city with high traffic density. METHODS: We used the Google Distance Matrix application programming interface to prospectively determine driving times incorporating current traffic conditions at 5-minute intervals between 9:00 AM and 4:55 PM during the first 4 months of 2018 between 4 pairs of clinics and hospitals in the University of Miami health system. Travel time distributions were modeled using lognormal and Burr distributions and compared using the absolute and signed differences for the median and the 0.9 quantile. Differences were evaluated using 2-sided, 1-group t tests and Wilcoxon signed-rank tests. We considered 5-minute signed differences between the distributions as managerially relevant. RESULTS: For the 80 studied combinations of origin-to-destination pairs (N = 4), day of week (N = 5), and the hour of departure between 10:00 AM and 1:55 PM (N = 4), the maximum difference between the median and 0.9 quantile travel time was 8.1 minutes. This contrasts with the previously published corresponding difference between the median and the 0.9 quantile of 74 minutes for case duration. Travel times were well fit by Burr and lognormal distributions (all 160 differences of medians and of 0.9 quantiles <5 minutes; P < .001). For each of the 4 origin-destination pairs, travel times at 12:00 PM were a reasonable approximation to travel times between the hours of 10:00 AM and 1:55 PM during all weekdays. CONCLUSIONS: During mid-day, when surgeons likely would travel between a clinic and an operating room facility, travel time variability is small compared to case duration prediction variability. Thus, afternoon operating room scheduling should not be restricted because of concern related to unpredictable travel times by surgeons. Providing operating room managers and surgeons with estimated travel times sufficient to allow for a timely arrival on 90% of days may facilitate the scheduling of additional afternoon cases especially at ambulatory facilities with substantial underutilized time.

Anxiety disorders in outpatient clinics of epilepsy in tertiary care hospitals: A meta-analysis.

BACKGROUND AND PURPOSE: Although anxiety disorders (ADs) occur frequently in people with epilepsy (PWE) and impair quality of life and treatment outcomes, current efforts to categorize and investigate AD subtypes in PWE remain insufficient. Thus, the present meta-analysis aimed to determine the current prevalence rates of any AD type and various AD subtypes in PWE managed by outpatient clinics. METHODS: MEDLINE, EMBASE, Cochrane Library, Web of Science, and SCOPUS were searched to identify and select studies that assessed the prevalence of ADs or individual AD subtypes in adult PWE under the routine care of outpatient epilepsy clinics in tertiary hospitals. Only studies that used gold-standard diagnostic tools for assessing ADs were included in this meta-analysis. RESULTS: The database search ultimately identified 15 studies, of which 9 provided current prevalence rates of any type of AD. The pooled estimated prevalence of any AD was 26.1 %. Of the 15 total studies, 13 provided current prevalence rates of generalized anxiety disorder (GAD), revealing an overall estimated prevalence of 18.2 %. In terms of current prevalence rates, GAD was highest, followed by agoraphobia, social phobia, panic disorder, and obsessive-compulsive disorder. CONCLUSIONS: Among PWE managed in the outpatient epilepsy clinics of tertiary care hospitals, the current prevalence of any AD was 26.1 %, and GAD was the most prevalent subtype of AD.

Trauma-related disorders in a low- to middle-income country: A four-year follow-up of outpatient trauma in Brazil.

Acute stress disorder (ASD) and post-traumatic stress disorder (PTSD) are developed from exposure to traumatic events including war, interpersonal violence and natural disasters. We investigated prevalence and trauma-related information in patients from an outpatient psychiatric unit in Brazil among 2014-2017. A prevalence of ASD/PTSD of 40.8% was found in 179 patients. Female, Caucasian, married, mostly educated during 10-12 years long and employed patients composed a main profile. The presence of any previous trauma in adulthood and childhood were related to ASD/PTSD with longer follow-up time. This study provides evidence of stress-related disorders in a heterogeneous environment.

Internalised stigma in adults with autism: A German multi-center survey.

The aim of this study was to evaluate the extent of internalised stigma and possible predictors in adults with a diagnosis of autism spectrum disorder (ASD). We measured internalised stigma in a sample of 149 adults with ASD and an IQ ≥70 (79.2% male, mean age 31.8 years), using the Brief Version of the Internalized Stigma of Mental Illness Scale (ISMI-10). The mean ISMI-10 score was 1.93 (SD=0.57), with 15.4% of participants reporting moderate or severe internalised stigma. Moderate or severe stigma was more frequent in persons aged ≥35 years (OR: 4.36), and in individuals with low educational level (OR: 6.00). IQ, sex and ASD diagnostic subtype (ICD-10) did not influence stigma severity. Compared to other mental disorders, the level of internalised stigma in adults with ASD without intellectual disability appears to be lower.

A comprehensive modelling framework to forecast the demand for all hospital services.

BACKGROUND: Because of increasing demand, hospitals in England are currently under intense pressure resulting in shortages of beds, nurses, clinicians, and equipment. To be able to effectively cope with this demand, the management needs to accurately find out how many patients are expected to use their services in the future. This applies not just to one service but for all hospital services. PURPOSE: A forecasting modelling framework is developed for all hospital's acute services, including all specialties within outpatient and inpatient settings and the accident and emergency (A&E) department. The objective is to support the management to better deal with demand and plan ahead effectively. METHODOLOGY/APPROACH: Having established a theoretical framework, we used the national episodes statistics dataset to systematically capture demand for all specialties. Three popular forecasting methodologies, namely, autoregressive integrated moving average (ARIMA), exponential smoothing, and multiple linear regression were used. A fourth technique known as the seasonal and trend decomposition using loess function (STLF) was applied for the first time within the context of health-care forecasting. RESULTS: According to goodness of fit and forecast accuracy measures, 64 best forecasting models and periods (daily, weekly, or monthly forecasts) were selected out of 760 developed models; ie, demand was forecasted for 38 outpatient specialties (first referrals and follow-ups), 25 inpatient specialties (elective and non-elective admissions), and for A&E. CONCLUSION: This study has confirmed that the best demand estimates arise from different forecasting methods and forecasting periods (ie, one size does not fit all). Despite the fact that the STLF method was applied for the first time, it outperformed traditional time series forecasting methods (ie, ARIMA and exponential smoothing) for a number of specialties. PRACTISE IMPLICATIONS: Knowing the peaks and troughs of demand for an entire hospital will enable the management to (a) effectively plan ahead; (b) ensure necessary resources are in place (eg, beds and staff); (c) better manage budgets, ensuring enough cash is available; and (d) reduce risk.

Prevalence of abnormal Alzheimer's disease biomarkers in patients with subjective cognitive decline: cross-sectional comparison of three European memory clinic samples.

INTRODUCTION: Subjective cognitive decline (SCD) in cognitively unimpaired older individuals has been recognized as an early clinical at-risk state for Alzheimer's disease (AD) dementia and as a target population for future dementia prevention trials. Currently, however, SCD is heterogeneously defined across studies, potentially leading to variations in the prevalence of AD pathology. Here, we compared the prevalence and identified common determinants of abnormal AD biomarkers in SCD across three European memory clinics participating in the European initiative on harmonization of SCD in preclinical AD (Euro-SCD). METHODS: We included three memory clinic SCD samples with available cerebrospinal fluid (CSF) biomaterial (IDIBAPS, Barcelona, Spain, n = 44; Amsterdam Dementia Cohort (ADC), The Netherlands, n = 50; DELCODE multicenter study, Germany, n = 42). CSF biomarkers (amyloid beta (Aß)42, tau, and phosphorylated tau (ptau181)) were centrally analyzed in Amsterdam using prespecified cutoffs to define prevalence of pathological biomarker concentrations. We used logistic regression analysis in the combined sample across the three centers to investigate center effects with regard to likelihood of biomarker abnormality while taking potential common predictors (e.g., age, sex, apolipoprotein E (APOE) status, subtle cognitive deficits, depressive symptoms) into account. RESULTS: The prevalence of abnormal Aß42, but not tau or ptau181, levels was different across centers (64% DELCODE, 57% IDIBAPS, 22% ADC; p < 0.001). Logistic regression analysis revealed that the likelihood of abnormal Aß42 (and also abnormal tau or ptau181) levels was predicted by age and APOE status. For Aß42 abnormality, we additionally observed a center effect, indicating between-center heterogeneity not explained by age, APOE, or the other included covariates. CONCLUSIONS: While heterogeneous frequency of abnormal Aß42 was partly explained by between-sample differences in age range and APOE status, the additional observation of center effects indicates between-center heterogeneity that may be attributed to different recruitment procedures. These findings highlight the need for the development of harmonized recruitment protocols for SCD case definition in multinational studies to achieve similar enrichment rates of preclinical AD.