Alexandra D. Frolkis

The prevalence of Parkinson's disease: A systematic review and meta‐analysis

Parkinsons Disease (PD) is a common neurodegenerative disorder. We sought to synthesize studies on the prevalence of PD to obtain an overall view of how the prevalence of this disease varies by age, by sex, and by geographic location. We searched MEDLINE and EMBASE for epidemiological studies of PD from 1985 to 2010. Data were analyzed by age group, geographic location, and sex. Geographic location was stratified by the following groups: 1) Asia, 2) Africa, 3) South America, and 4) Europe/North America/Australia. Meta‐regression was used to determine whether a significant difference was present between groups. Forty‐seven studies were included in the analysis. Meta‐analysis of the worldwide data showed a rising prevalence of PD with age (all per 100,000): 41 in 40 to 49 years; 107 in 50 to 59 years; 173 in 55 to 64 years; 428 in 60 to 69 years; 425 in 65 to 74 years; 1087 in 70 to 79 years; and 1903 in older than age 80. A significant difference was seen in prevalence by geographic location only for individuals 70 to 79 years old, with a prevalence of 1,601 in individuals from North America, Europe, and Australia, compared with 646 in individuals from Asia (P < 0.05). A significant difference in prevalence by sex was found only for individuals 50 to 59 years old, with a prevalence of 41 in females and 134 in males (P < 0.05). PD prevalence increases steadily with age. Some differences in prevalence by geographic location and sex can be detected.

Environment and the Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD), which consists of Crohn disease and ulcerative colitis, are chronic inflammatory conditions of the gastrointestinal tract. In genetically susceptible individuals, the interaction between environmental factors and normal intestinal commensal flora is believed to lead to an inappropriate immune response that results in chronic inflammation. The incidence of IBD have increased in the past century in developed and developing countries. The purpose of the present review is to summarize the current knowledge of the association between environmental risk factors and IBD. A number of environmental risk factors were investigated including smoking, hygiene, microorganisms, oral contraceptives, antibiotics, diet, breastfeeding, geographical factors, pollution and stress. Inconsistent findings among the studies highlight the complex pathogenesis of IBD. Additional studies are necessary to identify and elucidate the role of environmental factors in IBD etiology.

The Incidence of Parkinson's Disease: A Systematic Review and Meta-Analysis

Background: Parkinsons disease (PD) is a common neurodegenerative disorder. Epidemiological studies on the incidence of PD are important to better understand the risk factors for PD and determine the conditions natural history. Objective: This systematic review and meta-analysis examine the incidence of PD and its variation by age and gender. Methods: We searched MEDLINE and EMBASE for epidemiologic studies of PD from 2001 to 2014, as a previously published systematic review included studies published until 2001. Data were analyzed separately for age group and gender, and meta-regression was used to determine whether a significant difference was present between groups. Results: Twenty-seven studies were included in the analysis. Meta-analysis of international studies showed rising incidence with age in both men and women. Significant heterogeneity was observed in the 80+ group, which may be explained by methodological differences between studies. While males had a higher incidence of PD in all age groups, this difference was only statistically significant for those in the age range 60-69 and 70-79 (p < 0.05). Conclusion: PD incidence generally increases with age, although it may stabilize in those who are 80+.

Cumulative Incidence of Second Intestinal Resection in Crohn's Disease: A Systematic Review and Meta-Analysis of Population-Based Studies

OBJECTIVES:Approximately 50% of Crohn’s disease patients undergo an intestinal resection within 10 years of diagnosis. The risk of second surgery in Crohn’s disease and the influence of time are not well characterized. We performed a systematic review and meta-analysis to establish the risk of second abdominal surgery in patients with Crohn’s disease among patients who had a previous surgery.METHODS:We searched Medline, EMBASE, PubMed (March 2014), and conference proceedings for terms related to Crohn’s disease and intestinal surgery. We included population-based articles (n=11) and an abstract (n=1) reporting surgical risk for the overall study period and for 5 and 10 years after the first surgery for Crohn’s disease. We stratified studies by year (start year before vs. after 1980) to explore the role of time.RESULTS:For all population-based studies, the overall risk of second surgery was 28.7% (95% confidence interval (CI): 22.6–36.6%). The 5-year risk of second surgery was 24.2% (95% CI: 22.3–26.4%). The 10-year risk of second surgery was 35.0% (95% CI: 31.8–38.6%). A significant difference in the 10-year risk of second surgery was observed over time such that studies conducted after 1980 had a lower risk of second surgery (33.2%; 95% CI: 31.2–35.4%) compared with those that started before 1980 (44.6%; 95% CI: 37.7–52.7%).CONCLUSIONS:Approximately one-quarter of Crohn’s disease patients who have a first surgery also have a second, and the majority of these surgeries occur within 5 years of the first surgery. The 10-year risk of second surgery is significantly decreasing over time.

The Prevalence and Incidence of Dementia Due to Alzheimer’s Disease: a Systematic Review and Meta-Analysis

BACKGROUND Updated information on the epidemiology of dementia due to Alzheimers disease (AD) is needed to ensure that adequate resources are available to meet current and future healthcare needs. We conducted a systematic review and meta-analysis of the incidence and prevalence of AD. METHODS The MEDLINE and EMBASE databases were searched from 1985 to 2012, as well as the reference lists of selected articles. Included articles had to provide an original population-based estimate for the incidence and/or prevalence of AD. Two individuals independently performed abstract and full-text reviews, data extraction and quality assessments. Random-effects models were employed to generate pooled estimates stratified by age, sex, diagnostic criteria, location (i.e., continent) and time (i.e., when the study was done). RESULTS Of 16,066 abstracts screened, 707 articles were selected for full-text review. A total of 119 studies met the inclusion criteria. In community settings, the overall point prevalence of dementia due to AD among individuals 60+ was 40.2 per 1000 persons (CI95%: 29.1-55.6), and pooled annual period prevalence was 30.4 per 1000 persons (CI95%: 15.6-59.1). In community settings, the overall pooled annual incidence proportion of dementia due to AD among individuals 60+ was 34.1 per 1000 persons (CI95%: 16.4-70.9), and the incidence rate was 15.8 per 1000 person-years (CI95%: 12.9-19.4). Estimates varied significantly with age, diagnostic criteria used and location (i.e., continent). CONCLUSIONS The burden of AD dementia is substantial. Significant gaps in our understanding of its epidemiology were identified, even in a high-income country such as Canada. Future studies should assess the impact of using such newer clinical diagnostic criteria for AD dementia such as those of the National Institute on Aging-Alzheimers Association and/or incorporate validated biomarkers to confirm the presence of Alzheimer pathology to produce more precise estimates of the global burden of AD.

Postoperative complications and emergent readmission in children and adults with inflammatory bowel disease who undergo intestinal resection: a population-based study.

Background:Although the nature and frequency of postoperative complications after intestinal resection in patients with inflammatory bowel disease have been previously described, short-term readmission has not been characterized in population-based studies. We therefore assessed the risk of postoperative complications and emergent readmissions after discharge from an intestinal resection. Methods:We used a Canadian provincial-wide inpatient hospitalization database to identify 2638 Crohns disease (CD) and 559 ulcerative colitis (UC) admissions with intestinal resection from 2002 to 2011. We identified the cumulative risk of in-hospital complication and emergent readmission within 90 days after discharge along with predictors for both outcomes using a Poisson regression for binary outcomes. Results:The cumulative risks of in-hospital postoperative complications and 90-day emergent readmission were 23.8% and 12.6%, respectively in CD and 33.3% and 11.1%, respectively in UC. The predictors for in-hospital postoperative complications for CD and UC included older age, comorbidities, and open laparatomy for CD, additional predictors included emergent admission, stoma surgery, and concurrent resection of both small and large bowel. The predictors for 90-day readmission for CD included a postoperative complication (risk ratio, 1.61; 95% confidence interval, 1.30–2.01), emergent admission (risk ratio, 1.39; 95% confidence interval, 1.12–1.73), and stoma formation (risk ratio, 1.49; 95% confidence interval, 1.15–1.93) at the hospitalization requiring surgery. Conclusions:Readmission and postoperative complications are common after intestinal resection in CD and UC. Clinicians should closely monitor surgical patients who required emergent admission, undergo surgery with stoma formation, or develop in-hospital postoperative complications to anticipate need for readmission or interventions to prevent readmission.

The worldwide incidence and prevalence of primary brain tumors: a systematic review and meta-analysis

BACKGROUND Primary brain tumors are a heterogeneous group of benign and malignant tumors arising from the brain parenchyma and its surrounding structures. The epidemiology of these tumors is poorly understood. The aim of our study is to systematically review the latest literature on the incidence and prevalence of primary brain tumors. METHODS The systematic review and meta-analysis were conducted according to a predetermined protocol and established guidelines. Only studies reporting on data from 1985 onward were included. Articles were included if they met the following criteria: (i) original research, (ii) population based, (iii) reported an incidence or prevalence estimate of primary brain tumors. RESULTS From the 53 eligible studies overall, 38 were included in the meta-analysis. A random-effects model found the overall incidence rate of all brain tumors to be 10.82 (95% CI: 8.63-13.56) per 100 000 person-years. The incidence proportion estimates were heterogeneous, even among the same tumor subtypes, and ranged from 0.051 per 100 000 (germ cell tumors) to 25.48 per 100 000 (all brain tumors). There were insufficient data to conduct a meta-analysis of the prevalence of primary brain tumors. CONCLUSIONS There is a need for more accurate and comparable incidence and prevalence estimates of primary brain tumors across the world. A standardized approach to the study of the epidemiology of these tumors is needed to better understand the burden of brain tumors and the possible geographical variations in their incidence.

Upper-gastrointestinal bleeding secondary to peptic ulcer disease: incidence and outcomes.

AIM To evaluate the incidence, surgery, mortality, and readmission of upper gastrointestinal bleeding (UGIB) secondary to peptic ulcer disease (PUD). METHODS Administrative databases identified all hospitalizations for UGIB secondary to PUD in Alberta, Canada from 2004 to 2010 (n = 7079) using the International Classification of Diseases Codes (ICD-10). A subset of the data was validated using endoscopy reports. Positive predictive value and sensitivity with 95% confidence intervals (CI) were calculated. Incidence of UGIB secondary to PUD was calculated. Logistic regression was used to evaluate surgery, in-hospital mortality, and 30-d readmission to hospital with recurrent UGIB secondary to PUD. Co-variants accounted for in our logistic regression model included: age, sex, area of residence (i.e., urban vs rural), number of Charlson comorbidities, presence of perforated PUD, undergoing upper endoscopy, year of admission, and interventional radiological attempt at controlling bleeding. A subgroup analysis (n = 6356) compared outcomes of patients with gastric ulcers to those with duodenal ulcers. Adjusted estimates are presented as odds ratios (OR) with 95%CI. RESULTS The positive predictive value and sensitivity of ICD-10 coding for UGIB secondary to PUD were 85.2% (95%CI: 80.2%-90.2%) and 77.1% (95%CI: 69.1%-85.2%), respectively. The annual incidence between 2004 and 2010 ranged from 35.4 to 41.2 per 100000. Overall risk of surgery, in-hospital mortality, and 30-d readmission to hospital for UGIB secondary to PUD were 4.3%, 8.5%, and 4.7%, respectively. Interventional radiology to control bleeding was performed in 0.6% of patients and 76% of these patients avoided surgical intervention. Thirty-day readmission significantly increased from 3.1% in 2004 to 5.2% in 2010 (OR = 1.07; 95%CI: 1.01-1.14). Rural residents (OR rural vs urban: 2.35; 95%CI: 1.83-3.01) and older individuals (OR ≥ 65 vs < 65: 1.57; 95%CI: 1.21-2.04) were at higher odds of being readmitted to hospital. Patients with duodenal ulcers had higher odds of dying (OR = 1.27; 95%CI: 1.05-1.53), requiring surgery (OR = 1.73; 95%CI: 1.34-2.23), and being readmitted to hospital (OR = 1.54; 95%CI: 1.19-1.99) when compared to gastric ulcers. CONCLUSION UGIB secondary to PUD, particularly duodenal ulcers, was associated with significant morbidity and mortality. Early readmissions increased over time and occurred more commonly in rural areas.

The Association of Smoking and Surgery in Inflammatory Bowel Disease is Modified by Age at Diagnosis

Objectives:We assessed the association of smoking at diagnosis of inflammatory bowel disease (IBD) on the need for an intestinal resection.Methods:The Health Improvement Network was used to identify an inception cohort of Crohn’s disease (n=1519) and ulcerative colitis (n=3600) patients from 1999–2009. Poisson regression explored temporal trends for the proportion of newly diagnosed IBD patients who never smoked before their diagnosis and the risk of surgery within 3 years of diagnosis. Cox proportional hazard models assessed the association between smoking and surgery, and effect modification was explored for age at diagnosis.Results:The rate of never smokers increased by 3% per year for newly diagnosed Crohn’s disease patients (incidence rate ratio (IRR) 1.03; 95% confidence interval (CI): 1.02–1.05), but not for ulcerative colitis. The rate of surgery decreased among Crohn’s disease patients aged 17–40 years (IRR 0.96; 95% CI: 0.93–0.98), but not for ulcerative colitis. Smoking at diagnosis increased the risk of surgery for Crohn’s disease patients diagnosed after the age of 40 (hazard ratio (HR) 2.99; 95% CI: 1.52–5.92), but not for those diagnosed before age 40. Ulcerative colitis patients diagnosed between the ages of 17 and 40 years and who quit smoking before their diagnosis were more likely to undergo a colectomy (ex-smoker vs. never smoker: HR 1.66; 95% CI: 1.04–2.66). The age-specific findings were consistent across sensitivity analyses for Crohn’s disease, but not ulcerative colitis.Conclusions:In this study, the association of smoking and surgical resection was dependent on the age at diagnosis of IBD.

Risk of depression among patients with acne in the U.K.: a population‐based cohort study

DEAR EDITOR, Acne has been associated with adverse psychiatric symptoms. In dermatology outpatient clinics, approximately 25.2% of patients with acne experience some psychiatric morbidity. However, few studies have evaluated the clinically significant diagnostic category of major depressive disorder (MDD) among people with acne. Here, we investigated whether patients with acne are at an increased risk of developing MDD compared to the general population, using one of the largest electronic medical records databases in the world. A retrospective cohort study was conducted using data from The Health Improvement Network (THIN) (1986–2012), a large primary care database in the U.K. that also includes data from specialists. All individuals between 7 and 50 years of age with ≥ 1 Read codes (diagnostic codes linked to International Classification of Diseases codes) for acne were identified. A general population cohort without acne was also identified. The study was approved by the Conjoint Health Research Ethics Board at the University of Calgary (ID 24423) and from the Scientific Review Committee in the U.K. (ID 16THIN036), authorizing access to extract relevant data from THIN. A complete list of codes used to identify exposures, outcomes and covariates is available from the authors. All patients were followed from their start date for ≥ 2 years in THIN until the earliest of either their first MDD Read code (main outcome), transfer out of practice, death or end of data collection. Observations were censored at the end of follow-up in patients where MDD was not observed during the study period. To identify only incident cases, patients with an acne or MDD Read code prior to the start of follow-up were excluded. Baseline covariates at the start of follow-up included age (young ≤ 19; adult > 19 years), sex, obesity (BMI ≥ 30 kg m ), smoking status (never, former, current), alcohol use (yes or no), medical comorbidities using the Charlson Comorbidity Index (0 or ≥ 1 comorbidity) and socioeconomic status using the Townsend Deprivation Index (quintiles 1–5, with 1 least and 5 most deprivation).