Heterogeneity In Prevalence Estimates Research Articles

Prevalence of Cannabis Use Disorder: A Meta-Analysis of Population Surveys.

Epidemiologic surveys aim to estimate the population prevalence of cannabis use and cannabis use disorder. Prevalences estimates are important for understanding trends, such as the impact of policy change. Existing epidemiologic surveys have produced discrepant and potentially unreliable estimates. The current meta-analysis (PROSPERO CRD42022364818) aims to identify potential sources of unreliability in prevalence estimates of cannabis use and use disorder among the general population (aged 12+). There was no specific hypothesis about overall prevalence estimate, but we expected significant variability (i.e., heterogeneity) in estimates based on factors such as country, year of data collection, and specific methodological factors (e.g., diagnostic instrument). Systematic searches identified manuscripts and reports documenting nationally representative lifetime or past-year cannabis use disorder prevalence estimates. Meta-analysis was used to synthesize prevalence estimates, evaluate heterogeneity, and test moderators. There were 39 manuscripts/reports included in analyses which resulted in 259 unique prevalence estimates spanning 1980-2013 and an aggregated sample size of 973,281 individuals. Past-year and lifetime prevalence estimates for cannabis use were 12.83% (95% CI: 11.15%, 14.71%) and 38.31% (95% CI: 35.92%, 40.76%) and those for cannabis use disorder were 2.59% (95% CI:2.30%, 2.90%) and 6.77% (95% CI: 4.89%, 9.30%), respectively. There was significant heterogeneity in estimates, which was partially explained by factors such as country, year of data collection, and methodological characteristics. The significant heterogeneity in prevalence estimates as a function of methodological characteristics raises concerns about the generalizability of estimates. Recommendations for enhancing validity and reliability of these estimates are offered.

Tobacco use and behaviour among South African adolescents and young adults: systematic review and meta-analysis

ObjectiveTobacco use, particularly the initiation of smoking during adolescence and young adulthood, represents a significant public health concern in South Africa. This study aims to conduct a comprehensive review of...

A systematic review and meta-analysis of prevalence and clinical features of upper gastrointestinal (UGI) tract Crohn's disease in adults compared to non-UGI types.

Crohn's disease is an inflammatory condition that affects the gastrointestinal (GI) system. This study aimed to determine the prevalence of upper gastrointestinal Crohn's disease (UGICD) and compare its features to non-UGICD types. We conducted a systematic search in the databases PubMed, Web of Science, Scopus, and Google Scholar. The heterogeneity of prevalence estimates was examined, subgroup analyses were carried out, and meta-analyses were conducted using random-effects modeling. Prognostic data were qualitatively reviewed and combined. Two-thousand nine-hundred and forty studies were retrieved and 32 studies were included in the final analysis. Pooled prevalence of UGICD was 15% (CI: 11-18%) among 14 509 patients. UGICD prevalence did not show any significant increase with time (P = 0.45). The most prevalent (38%, CI: 30-47%) behavior of UGICD was B1 (nonstricturing-nonpenetrating), while the most common concurrent location was L3 (ileocolon) with a prevalence of 47% (CI: 34-59%). UGICD patients had higher stricturing phenotype (B2) compared to non-UGICD (0.38 vs 0.30; P = 0.03). There was no significant difference in the prevalence of UGICD between patients classified according to the Montreal or Vienna classification. Stricturing phenotype was more common among Asian patients compared to Western patients (0.44 vs 0.24; P < 0.001). UGICD was a risk factor for surgery and drug therapy and was associated with an aggressive course of the disease and more resections. Pooled prevalence of UGICD was 15%. Nonstricturing-nonpenetrating type was the most prevalent UGICD. UGICD patients had more complications and worse outcomes compared to non-UGICD patients.

Prevalence of Functioning Adrenal Incidentalomas: A Systematic Review and Meta-analysis.

Adrenal hyperfunction is associated with an increased risk of cardiometabolic complications in subjects with adrenal incidentaloma (AI). Reliable prevalence estimates of functioning AIs are important to direct resources allocations. To assess the prevalence of autonomous/possible autonomous cortisol secretion (ACS), primary aldosteronism (PA), pheochromocytoma (PHEO), and Cushing syndrome (CS) in patients with AI. We performed a comprehensive search of multiple databases (PubMed, Ovid MEDLINE, Web of Science) for potentially relevant studies without language restriction, up to February 2022. Of the 1661 publications evaluated at title and abstract levels, 161 were examined as full text and 36 were included. Study level clinical data were extracted by 3 independent reviewers. The overall prevalence of functioning AIs was 27.5% (95% CI 23.0, 32.5). ACS/possible ACS, with a prevalence of 11.7% (95% CI 8.6, 15.7), was the most frequent hormonal alteration, while PA occurred in 4.4% of the patients (95% CI 3.1, 6.2). Subgroup analysis showed that PA was more prevalent in patients from Asia than in patients from Europe/America; in contrast, ACS/possible ACS had a lower prevalence in Asian countries. At meta-regression analysis, the prevalence of ACS/possible ACS was influenced by the proportion of female patients, while the prevalence of PA was positively associated with the proportion of patients with hypertension and the publication year. Finally, PHEO and CS prevalence were 3.8% (95% CI 2.8, 5.0) and 3.1% (95% CI 2.3, 4.3) respectively. This meta-analysis provides extensive data on the prevalence of functioning AIs and the factors affecting heterogeneity in prevalence estimates.

Prevalence and Clinical Characteristics of Nontuberculous Mycobacteria in Patients with Bronchiectasis: A Systematic Review and Meta-Analysis

Background: Although international bronchiectasis guidelines recommended screening of nontuberculous mycobacteria (NTM) both at initial evaluation and prior to administration of macrolide treatment, data regarding NTM in bronchiectasis remain elusive. Objective: To establish the prevalence, species, and clinical features of NTM in adults with bronchiectasis. Methods: We searched PubMed, Embase, and Web of Science for studies published before April 2020 reporting the prevalence of NTM in adults with bronchiectasis. We only included studies with bronchiectasis confirmed by computed tomography and NTM identified by mycobacteria culture or molecular methods. Random-effects meta-analysis was employed. Results: Of the 2,229 citations identified, 21 studies, including 12,454 bronchiectasis patients were included in the final meta-analysis. The overall pooled prevalence of NTM isolation and pulmonary NTM disease were 7.7% (5.0%–11.7%) (n/N = 2,677/12,454) and 4.1% (1.4%–11.4%) (n/N = 30/559), respectively, with significant heterogeneity (I2 = 97.7%, p < 0.001 and I2 = 79.9%, p = 0.007; respectively). The prevalence of NTM isolation varied significantly among different geographical regions with the highest isolation at 50.0% (47.3%–52.7%) reported in the United States. Mycobacterium avium complex and Mycobacterium abscessus complex accounted for 66 and 16.6% of all species, respectively. Some clinical and radiological differences were noted between patients with and without the presence of NTM isolation although the results are inconsistent. Conclusions: Heterogeneity in prevalence estimates of NTM isolation indicated that both local surveys to inform development of clinical services tailored to patients with bronchiectasis and population-based studies are needed. The clinical features associated with NTM in bronchiectasis and their incremental utility in studying the association is unknown and merits further investigation.

Measurement and prevalence of sexual harassment in low- and middle-income countries: a systematic review and meta-analysis

ObjectivesWe synthesise evidence on sexual harassment from studies in low-income and middle-income countries (LMICs) to estimate its prevalence and conduct a meta-analysis of the association between sexual harassment and depressive...

Use of community-based reference ranges to estimate the prevalence of polycystic ovary syndrome by the recognised diagnostic criteria, a cross-sectional study.

Does the application of reference ranges for sex steroids and the modified Ferriman-Gallwey (mFG) scale established in the community from which the study sample was drawn, combined with the most conservative polycystic ovary morphology (PCOM) criteria to the recognised diagnostic criteria for polycystic ovary syndrome (PCOS) improve the certainty of diagnosis of PCOS in non-healthcare-seeking women? Despite application of the stringent definitions of the elements used to diagnose PCOS in a non-healthcare seeking community-based sample, the risk of diagnostic uncertainty remains. There is heterogeneity in prevalence estimates for PCOS due, in part, to lack of standardisation of the elements comprising the recognised National Institutes of Health (NIH), Rotterdam and Androgen Excess Society (AE-PCOS) diagnostic criteria. The AE-PCOS Society proposed refinements to the definitions of biochemical androgen excess and PCOM that can now be incorporated into these sets of diagnostic criteria to estimate PCOS prevalence. An Australian cross-sectional study of 168 non-healthcare-seeking women. The 168 included women were aged 18-39 years, euthyroid and normoprolactinemic, not recently pregnant, breast feeding or using systemic hormones. Each provided menstrual history and assessment of the mFG, had measurement of sex steroids by liquid chromatography, tandem mass spectrometry, and a pelvic ultrasound. The presence of PCOS was determined using modified (m) NIH, Rotterdam, and AE-PCOS criteria according to AE-PCOS Society recommendations. Overall, 10.1% of the included participants met the mNIH PCOS criteria, which requires the presence of menstrual dysfunction, while 18.5% met the mRotterdam and 17.5% the AE-PCOS criteria, with the latter requiring hyperandrogenism. Eight of the 27 participants with menstrual dysfunction, 10 of 31 women with PCOM, and 39 of 68 women with hyperandrogenism had no other feature of PCOS. Of the 19 participants with hyperandrogenaemia, 10 met the mNIH criteria (52.5%) and 14 met both the mRotterdam and AE-PCOS criteria (78.9%). Women who had the combination of hyperandrogenism and PCOM explained the greatest discrepancy between the mNIH and the other criteria. Clinical androgenisation relied on participant self-assessment, which has been shown to be valid when compared with clinician assessment. The sample size was a function of both the strict inclusion criteria and the requirements of non-healthcare-seeking women having a blood draw and pelvic ultrasound which may have introduced a selection bias. Despite applying stringent cut-offs for serum androgens, the mFG scale and the ovarian follicle count, these criteria remain arbitrary. Accordingly, healthy women may be captured by these criteria, and misidentified as having PCOS, while women with the condition may be missed. Consequently, PCOS remains a diagnosis to be made with care. The study was supported by the Grollo-Ruzzene Foundation. Dr S.R.D. is an NHMRC Senior Principal Research Fellow (Grant no. 1135843). S.R.D. has been paid for developing and delivering educational presentations for Besins Healthcare, BioFemme and Pfizer Australia, has been on Advisory Boards for Theramex, Abbott Laboratories, Mayne Pharmaceuticals and Roche and a consultant to Lawley Pharmaceuticals and Que Oncology and has received has received institutional grant funding for Que Oncology research; there are no other relationships or activities that could appear to have influenced the submitted work. N/A.

Epidemiology of malaria among HIV/AIDS patients in sub-Saharan Africa: A systematic review and meta-analysis of observational studies

Malaria related HIV morbidity and death is a concern in sub-Saharan Africa. Understanding the epidemiology of malaria among people living with HIV is vital for adequate intervention. We conducted a systematic review and meta-analysis to estimate the prevalence of malaria in HIV patients in sub-Saharan Africa. We searched PubMed, AJOL, Web of Science and Google Scholar databases. The overall pooled prevalence and pooled Odds Ratio (OR) with their 95% Confidence Intervals (CI) were estimated using the random-effects model and potential causes of heterogeneity in prevalence estimates were investigated using subgroup and meta-regression analysis. 58 studies, including 23,911 HIV patients, were identified between January 1990 and October 2020. The overall pooled prevalence of malaria in HIV patients was 22.7% (95% CI 18.0; 28.1). The Prevalence of malaria among HIV/AIDS patients was 33.1%, 30.2%, 15.3%, and 12.6% in Southern, Western, Central, and Eastern regions of SSA respectively. Prevalence of malaria in the central and western was higher [26.7% (95% CI 20.6; 33.9)] than 13.6% reported in the southern and eastern regions (95% CI 8.8; 20.5). There was a significant decrease in malaria prevalence among HIV/AIDS patients in the Eastern and Southern SSA regions from 21.9% (95% CI 15.5; 30.0) in the 2000-2010 period to 9.7% (95% CI 5.5-16.4) in the post-2010 period compared to the central and western regions. HIV infected patients with low CD4 + T cell count (CD4 < 200 cells/mm3) were 2.19 times more likely to become infected with malaria than those with high CD4 + T cell count (CD4 ≥ 200 cells/mm3) (pooled odds ratio (POR): 2.19 (95%CI 1.20;3.98), while patients on antiretroviral therapy (POR): 0.37 (0.23; 0.59), and in WHO clinical stages I and II (POR): 0.64 (0.28; 1.46), had a lower odds of been infected with malaria. Our review suggests that due consideration should be given to malaria among HIV/AIDS patients in SSA. In particular, the assessment and improvement of preventive measures for malaria/HIV co-infection in high-prevalence regions is important. For the treatment of both diseases, prophylaxis with cotrimoxazole and antiretroviral therapy should also be encouraged.

Diagnosing type 2 diabetes using Hemoglobin A1c: a systematic review and meta-analysis of the diagnostic cutpoint based on microvascular complications

AimsDiabetic microvascular complications of retinopathy, nephropathy and neuropathy may occur at hemoglobin A1c levels (HbA1c) below the 6.5% (48 mmol/mol) diagnostic threshold. Our objective was to assess the validity of the HbA1c diagnostic cutpoint of 6.5% based upon published evidence of the prevalence of retinopathy, nephropathy and neuropathy as markers of diabetes.MethodsData Sources PubMed, Embase, Cochrane, Scopus and CINAHL from 1990-March 2019, grey literature sources. Study Selection All studies reported after 1990 (to ensure standardized HbA1c values) where HbA1c levels were presented in relation to prevalence of retinopathy, nephropathy or neuropathy in subjects not known to have diabetes. Data Extraction Studies were screened independently, data abstracted, and risk of bias appraised. Data Synthesis Data were synthesized using HbA1c categories of < 6.0% (< 42 mmol/mol), 6.0–6.4% (42–47 mmol/mol) and ≥ 6.5% (≥ 48 mmol/mol). Random-effects meta-analyses were conducted for retinopathy, nephropathy and neuropathy prevalence stratified by HbA1c categories. Random-effects multivariable meta-regression was conducted to identify predictors of retinopathy prevalence and sources of between-study heterogeneity.ResultsPooled mean prevalence was: 4.0%(95% CI: 3.2–5.0%) for retinopathy, 10.5% (95% CI: 4.0–19.5%) for nephropathy, 2.5% (95% CI: 1.1–4.3%) for neuropathy. Mean prevalence when stratified for HbA1c < 6.0%, 6.0–6.4% and ≥ 6.5% was: retinopathy: 3.4% (95% CI: 1.8–5.4%), 2.3% (95% CI: 1.6–3.2%) and 7.8%(95% CI: 5.7–10.3%); nephropathy: 7.1% (95% CI: 1.7–15.9%), 9.6% (95% CI: 0.8–26.4%) and 17.1% (95% CI: 1.0–46.9%); neuropathy: 2.1% (95% CI: 0.0–6.8%), 3.4% (95% CI: 0.0–11.6%) and 2.8% (95% CI: 0.0–12.8%). Multivariable meta-regression showed HbA1c ≥ 6.5% (OR: 4.05; 95% CI: 1.92–8.57%), age > 55 (OR: 3.23; 95% CI 1.81–5.77), and African-American race (OR: 10.73; 95% CI: 4.34–26.55), to be associated with higher retinopathy prevalence. Marked heterogeneity in prevalence estimates was found across all meta-analyses (Cochran’s Q-statistic p < 0.0001).ConclusionsThe prevalence of nephropathy and moderate retinopathy was increased in subjects with HbA1c values ≥ 6.5% confirming the high specificity of this value for diagnosing T2DM; however, at HbA1c < 6.5% retinopathy increased at age > 55 years and, most strikingly, in African-Americans, suggesting there may be excess microvascular complication prevalence (particularly nephropathy) in individuals below the diabetes diagnostic threshold.

Prevalence of co-occurring mental health diagnoses in the autism population: a systematic review and meta-analysis

Co-occurring mental health or psychiatric conditions are common in autism, impairing quality of life. Reported prevalences of co-occurring mental health or psychiatric conditions in people with autism range widely. Improved prevalence estimates and identification of moderators are needed to enhance recognition and care, and to guide future research. In this systematic review and meta-analysis, we searched MEDLINE, Embase, PsycINFO, Scopus, Web of Science, and grey literature for publications between Jan 1, 1993, and Feb 1, 2019, in English or French, that reported original research using an observational design on the prevalence of co-occurring mental health conditions in people with autism and reported confirmed clinical diagnoses of the co-occurring conditions and autism using DSM or ICD criteria. For co-occurring mental health conditions reported with at least 15 datapoints (studies), we assessed risk of bias and we determined pooled estimates of prevalence for different co-occurring conditions in autism using random-effects models, and descriptively compared these with prevalence estimates for the general population from the literature (post hoc). We investigated heterogeneity in prevalence estimates using random-effects meta-regression models. This systematic review is registered with PROSPERO, CRD42018103176. Of 9746 unique studies identified, 432 were selected for full-text review. 100 studies were eligible for inclusion in our qualitative synthesis, of which 96 were included in our meta-analyses. 11 categories of co-occurring conditions were investigated, of which eight conditions were included in the meta-analyses and three were descriptively synthesised (ie, trauma and stressor-related disorders, substance-related and addictive disorders, and gender dysphoria). From our meta-analyses, we found overall pooled prevalence estimates of 28% (95% CI 25-32) for attention-deficit hyperactivity disorder; 20% (17-23) for anxiety disorders; 13% (9-17) for sleep-wake disorders; 12% (10-15) for disruptive, impulse-control, and conduct disorders; 11% (9-13) for depressive disorders; 9% (7-10) for obsessive-compulsive disorder; 5% (3-6) for bipolar disorders; and 4% (3-5) for schizophrenia spectrum disorders. Estimates in clinical sample-based studies were higher than in population-based and registry-based studies, and these estimates were mostly higher than those in the general population (post hoc). Age, gender, intellectual functioning, and country of study were associated with heterogeneity in prevalence estimates, yet remaining heterogeneity not explained was still substantial (all I2 >95%). Co-occurring mental health conditions are more prevalent in the autism population than in the general population. Careful assessment of mental health is an essential component of care for all people on the autism spectrum and should be integrated into clinical practice. Academic Scholars Awards, Department of Psychiatry, University of Toronto; O'Brien Scholars Program, Slaight Family Child and Youth Mental Health Innovation Fund, and The Catherine and Maxwell Meighen Foundation via the Centre for Addiction and Mental Health Foundation.

Prevalence of amblyopia in congenital blepharoptosis: a systematic review and Meta-analysis.

To conduct a systematic review and Meta-analysis of the published literature to evaluate the pooled prevalence rate of amblyopia in patients with congenital ptosis. We searched the PubMed, Embase, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang Data, and Chongqing VIP databases for studies reporting the prevalence of amblyopia in patients with congenital ptosis. The reference lists of relevant studies were scanned. Heterogeneity of effect sizes across studies was tested. We calculated prevalence ratios to compare prevalence estimates for different causes of amblyopia in patients with congenital ptosis, as well as for different geographical regions, year of publication and sample size in subgroup analyses. A systematic review and Meta-analysis were performed. We identified 29 eligible surveys with a total population of 2436. Prevalence rates of amblyopia ranged from 13.8% to 69%. We noted substantial heterogeneity in prevalence estimates for amblyopia in congenital ptosis (Cochran's χ 2 significant at P<0.0001; I 2=90%). The pooled prevalence using random-effects models of 29 studies was 32.8% (95%CI: 27.3%-38.4%) in the overall population. Compared to the overall pooled prevalence, amblyopia prevalence was higher in studies in which only subjects with blepharophimosis syndrome were included. We confirm that nearly one-third of congenital ptosis patients are suffering from or at risk for amblyopia. Patients with blepharophimosis syndrome are more likely to develop amblyopia. The identification and management of amblyopia should be integral to the treatment of congenital ptosis.

Gut microbiome–targeted therapies in nonalcoholic fatty liver disease: a systematic review, meta-analysis, and meta-regression

Preclinical evidence suggests that modulation of the gut microbiome could represent a new therapeutic target in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the most current evidence for liver-specific and metabolic effects of microbiome-targeted therapies (MTTs) in persons with NAFLD. We searched multiple electronic databases for randomized controlled trials (RCTs) published from January 1, 2005 to December 1, 2018 that enrolled persons with NAFLD who received MTT rather than placebo or usual care. MTT was defined as antibiotics, probiotics, synbiotics, or fecal microbiota transplantation (FMT). Clinical outcomes were pooled with the use of random-effects models and heterogeneity was assessed with the I2 statistic. A random-effects meta-regression was performed to determine sources of heterogeneity in prevalence estimates between studies. Twenty-one RCTs (1252 participants) were included; 9 evaluated probiotics and 12 evaluated synbiotics, with treatment duration ranging from 8 to 28 wk. No RCTs examined the efficacy of antibiotics or FMT. Probiotics/synbiotics were associated with a significant reduction in alanine aminotransferase activity [ALT, weighted mean difference (WMD): -11.23 IU/L; 95% CI: -15.02, -7.44 IU/L] and liver stiffness measurement (LSM) by elastography (reflecting inflammation and fibrosis) (WMD: -0.70 kPa; 95% CI: -1.00, -0.40 kPa), although analyses showed heterogeneity (I2=90.6% and I2=93.4%, respectively). Probiotics/synbiotics were also associated with increased odds of improvement in hepatic steatosis, as graded by ultrasound (OR: 2.40; 95% CI: 1.50, 3.84; I2=22.4%). No RCTs examined sequential liver biopsy findings. Probiotics (WMD: -1.84; 95% CI: -3.30, -0.38; I2=23.6%), but not synbiotics (WMD: -0.85; 95% CI: -2.17, 0.47; I2=96.6%), were associated with a significant reduction in body mass index. The use of probiotics/synbiotics was associated with improvement in liver-specific markers of hepatic inflammation, LSM, and steatosis in persons with NAFLD. Although promising, given the heterogeneity in pooled analyses, additional well-designed RCTs are needed to define the efficacy of probiotics/synbiotics for treatment of NAFLD. This study was registered with PROSPERO as CRD42018091455.

Prevalence of nonsuicidal self-injury in chinese middle school and high school students: A meta-analysis.

Recent studies have revealed a high rate of nonsuicidal self-injury (NSSI) behavior in Chinese students, but quantitative syntheses of pooled prevalence are sparse. There have been several NSSI prevalence meta-analyses in other populations. However, given the existence of cultural diversity, racial difference, educational system difference and so on, these results may not be ideal for Chinese populations. Furthermore, the above-mentioned meta-analyses did not include Chinese database which may have led to unintentional bias. Thus, we conducted this meta-analysis to estimate the prevalence of NSSI in Chinese middle-school students.The databases searched included PubMed, Embase, Web of Science, CBM (Chinese database), Chinese National Knowledge Infrastructure (CNKI), Wanfang Data (Chinese database) and the Weipu database (Chinese database). The search terms included: self-injury/self-harm/self-abuse/nonsuicidal self-injury/deliberate self-harm, adolescen∗/youth/teen/students, and China/Chinese. All relevant articles published between January 2000 to November 2017, in either Chinese or English, were included. Two investigators were engaged in this process, and any disagreements were settled by a third investigator. A random effects model was then used to calculate the pooled prevalence.A total of 420 studies with 160,348 participants were retrieved. The pooled prevalence was 22.37% (95% CI: 18.84%–25.70%). Substantial heterogeneity in prevalence estimates was revealed. Subgroup analyses showed that the pooled estimate of prevalence of life time NSSI was 14.5% (95%CI: 0.06%–22.7%), and 6–24 months NSSI was23.3% (95%CI: 20.5%–26.1%). The prevalence for males was 20.6% (95% CI: 16.1%–25.0%), and for females was 21.9% (95% CI: 17.6%–26.2%).The prevalence of NSSI in Chinese middle-school students is relatively high. More attention should be paid to the current situation.

The double burden of malnutrition among adolescents: analysis of data from the Global School-Based Student Health and Health Behavior in School-Aged Children surveys in 57 low- and middle-income countries

Adults and young children in countries experiencing the nutrition transition are known to be affected simultaneously by undernutrition and overnutrition. Adolescence is a critical period for growth and development. Yet, it is unknown to what extent this double burden of malnutrition affects adolescents in low- and middle-income countries (LMICs) and the macrolevel contextual factors associated with the double burden of malnutrition. The aim was to quantify the magnitude of the double burden of malnutrition among adolescents and to examine the potential sources of heterogeneity in prevalence estimates across LMICs. We used individual-participant data from the Global School-Based Student Health and Health Behavior in School-Aged Children surveys conducted in 57 LMICs between 2003 and 2013, comprising 129,276 adolescents aged 12-15 y. Pooled estimates of stunting, thinness, or both; overweight or obesity; and concurrent stunting and overweight or obesity were calculated overall, by regions, and stratified by sex, with random-effects meta-analysis. Guided by UNICEF's conceptual framework for child malnutrition, we used ecological linear regression models to examine the association between macrolevel contextual factors (internal conflict, lack of democracy, gross domestic product, food insecurity, urbanization, and survey year) and stunting, thinness, and overweight and obesity prevalence, respectively. The prevalence of stunting was 10.2% (95% CI: 8.3%, 12.2%) and of thinness was 5.5% (95% CI: 4.3%, 6.9%). The prevalence of overweight or obesity was 21.4% (95% CI: 18.6%, 24.2%). Between 38.4% and 58.7% of the variance in adolescent malnutrition was explained by macrolevel contextual factors. The prevalence of concurrent stunting and overweight or obesity was 2.0% (95% CI: 1.7%, 2.5%). The double burden of malnutrition among adolescents in LMICs is common. Context-sensitive implementation and scale-up of interventions and policies for the double burden of malnutrition are needed to achieve the Sustainable Development Goal to end malnutrition in all of its forms by 2030. This trial was registered at clinicaltrials.gov as NCT03346473.

Understanding variation in prevalence estimates of polycystic ovary syndrome: a systematic review and meta-analysis.

Polycystic ovary syndrome (PCOS) prevalence estimates vary when different diagnostic criteria are applied. Lack of standardization of individual elements within these criteria may contribute to prevalence differences. A systematic review of studies reporting prevalence of PCOS, using at least one of the National Institutes of Health (NIH), Rotterdam or Androgen Excess Society (AE-PCOS) criteria, was conducted. The aim was to investigate the impact on prevalence reporting of different definitions of the clinical elements for PCOS diagnosis. A systematic search of Ovid MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Emcare and BIOSIS was conducted. The search was limited to English language and studies published between January 1990 and January 2018. Included articles needed to define PCOS by at least one of the NIH, Rotterdam or AE-PCOS criteria, be of an unselected population and be published as a full text article. Risk-of-bias was assessed. A total of 21 studies met the inclusion criteria. The random-effects pooled prevalence of PCOS in studies that used the NIH criteria (7% [95% CI: 6-7%]), was significantly different from that identified in studies that used the Rotterdam criteria (12% [95% CI: 10-15%], P < 0.0001) but not studies that used the AE-PCOS criteria (10% [95% CI: 6-13%], P = 0.075). The pooled estimates for Rotterdam and AE-PCOS were not significantly different from each other (P = 0.201). Pooled prevalence estimates were compared between studies separated on the basis of: oligo-amenorrhoea vs oligo-amenorrhoea plus short cycles, clinical androgen excess requiring hirsutism vs any clinical androgen excess, use of different versions and cut-offs for the Ferriman-Gallwey (F-G) score, and inclusion vs non-inclusion of oral contraceptive users. There were no statistically significant differences for any of these comparisons. There was insufficient information to allow subgroup analyses of definitions of polycystic ovaries. Inclusion of ovarian morphology results in statistically significantly higher pooled prevalence estimates for PCOS. Heterogeneity in prevalence estimates for PCOS reflect the broad clinical spectrum of the condition, lack of standardization of the elements within each set of diagnostic criteria and the use of a range of diagnostic cut-offs, as well as potential differences between study populations. The use of different definitions for anovulation and clinical androgen excess did not appear to contribute to differences in the estimated prevalence of PCOS in this study. However, as the number of studies in most of the comparison groups was small, real differences may have been missed. Uncertainty surrounding the diagnosis of PCOS urgently needs to be addressed in order to provide clinicians and their patients with greater diagnostic certainty, and hence reduce inappropriate labelling and the potential psychological harm that may accompany misdiagnosis.

Apolipoprotein E e4 Allele Is Associated with Subjective Cognitive Decline: A Meta-Analysis

Background and Purpose: Subjective cognitive decline (SCD) is a condition associated with increased risk of Alzheimer’s disease. This study performs a meta-analysis to estimate the prevalence of the Apolipoprotein E e4 (APOE e4) allele in SCD and the association of APOE e4 with SCD. Methods: The MEDLINE, EMBASE, and Cochrane Library databases were searched. Meta-analyses were conducted using STATA 12.0 software. When significant heterogeneity was present (I² >50% and p < 0.05), we conducted stratified and meta-regression analyses to explore possible reasons for heterogeneity. Results: We selected a total of 28 studies that were conducted in Australia, the United States, northern Europe, middle Europe, southern Europe, and Asia. The sample size of the SCD group was 6,044. Thirteen studies included a healthy control group (total control cohort of 3,822), whereas the remaining 15 studies were single-arm studies of SCD groups. The APOE e4 allele was associated with SCD (OR 1.12 [1.00–1.25]; p = 0.04). The pooled estimate for APOE e4 carrier prevalence was 32% (95% CI 28–35). Due to the significant heterogeneity in prevalence estimates, we performed stratified and meta-regression analyses and found that age and northern European residency were significantly associated with heterogeneity. Conclusion: The results of this meta-analysis indicate a weak association between APOE e4 and SCD. Age and northern European residency are the critical factors that determine heterogeneity in the APOE e4-associated prevalence of SCD.

Global Prevalence of Spondyloarthritis: A Systematic Review and Meta-Regression Analysis.

To summarize the prevalence of spondyloarthritis (SpA) and its subtypes in the general population, and to identify demographic and methodologic characteristics that might explain heterogeneity in prevalence estimates. A systematic literature search was performed to identify relevant articles. Risk of bias was assessed and data were extracted. Pooled prevalences were calculated. Potential sources of heterogeneity were explored by subgroup analysis and meta-regression analysis. The prevalence of SpA ranged from 0.20% (95% confidence interval [95% CI] 0.00-0.66) in South-East Asia to 1.61% (95% CI 1.27-2.00) in Northern Arctic communities; the prevalence of ankylosing spondylitis (AS) from 0.02% (95% CI 0.00-0.21) in Sub-Saharan Africa to 0.35% (95% CI 0.24-0.48) in Northern Arctic communities; and the prevalence of psoriatic arthritis (PsA) from 0.01% (95% CI 0.00-0.17) in the Middle East to 0.19% (95% CI 0.16-0.32) in Europe. The following characteristics were significantly associated with variation in prevalence of SpA, AS, and/or PsA: proportion of females, mean age of the sample, geographic area and setting (demographic characteristics), year of data collection, case finding, and case ascertainment (methodologic characteristics). For the other SpA subgroups, too few studies were available to conduct a meta-analysis, but prevalence estimates of reactive arthritis (range 0.0-0.2%), SpA related to inflammatory bowel disease (range 0.0-0.1%), and undifferentiated SpA (range 0.0-0.7%) were generally low. SpA is a common disease, but with large variation in reported prevalence estimates, which can partly be explained by differences in demographic and methodologic characteristics. Particularly, geographic area as well as case finding account for a substantial part of the heterogeneity.

Prevalence of Depression among Chinese University Students: A Meta-Analysis.

BackgroundDepression is a major mental health issue worldwide, and university students with heavy burdens of study are at a high risk for depression. While a number of studies have been conducted regarding depression among university students in China, there is a lack of information regarding the national prevalence of depression among Chinese university students. Therefore, we performed a meta-analysis to statistically pool the prevalence of depression among Chinese university students.MethodsA systematic search of scientific databases was conducted, including Chinese Web of Knowledge, Embase, PubMed, Wanfang (a Chinese database) and Weipu (a Chinese database) to find relevant publications published between 1995 and December 2015. This was supplemented by a secondary review of the reference lists of all retrieved papers to find additional relevant citations. Studies published in either English or Chinese that provided prevalence estimates of depression in Chinese university students were considered. Prevalence estimates of each eligible study were extracted and pooled in our meta-analysis using a random-effects model.ResultsA total of 39 studies conducted between 1997 and 2015 including 32,694 university students were analyzed. Our results indicate that the overall prevalence of depression among Chinese university students is 23.8% (95% CI: 19.9%–28.5%). Substantial heterogeneity in prevalence estimates was noted. Subgroup analysis revealed that the prevalence of depression among medical students is higher than among other students.ConclusionsOverall, the prevalence of depression among Chinese university students is exceedingly high. This suggests that it is imperative that more attention be given to the development of appropriate mental healthcare strategies for university students in China.

A meta-analysis of the worldwide prevalence of pica during pregnancy and the postpartum period.

Although pica has long been associated with pregnancy, the exact prevalence in this population remains unknown. To estimate the prevalence of pica during pregnancy and the postpartum period, and to explain variations in prevalence estimates by examining potential moderating variables. PsycARTICLES, PsycINFO, PubMed, and Google Scholar were searched from inception to February 2014 using the keywords pica, prevalence, and epidemiology. Articles estimating pica prevalence during pregnancy and/or the postpartum period using a self-report questionnaire or interview were included. Study characteristics, pica prevalence, and eight potential moderating variables were recorded (parity, anemia, duration of pregnancy, mean maternal age, education, sampling method employed, region, and publication date). Random-effects models were employed. In total, 70 studies were included, producing an aggregate prevalence estimate of 27.8% (95% confidence interval 22.8-33.3). In light of substantial heterogeneity within the study model, the primary focus was identifying moderator variables. Pica prevalence was higher in Africa compared with elsewhere in the world, increased as the prevalence of anemia increased, and decreased as educational attainment increased. Geographical region, anemia, and education were found to moderate pica prevalence, partially explaining the heterogeneity in prevalence estimates across the literature.

Prevalence of non-HIV cancer risk factors in persons living with HIV/AIDS: a meta-analysis.

The burden of cancer among persons living with HIV/AIDS (PLWHA) is substantial and increasing. We assessed the prevalence of modifiable cancer risk factors among adult PLWHA in Western high-income countries since 2000. Meta-analysis. We searched PubMed to identify articles published in 2011-2013 reporting prevalence of smoking, alcohol consumption, overweight/obesity, and infection with human papillomavirus (HPV), hepatitis C virus (HCV) and hepatitis B virus (HBV) among PLWHA. We conducted random effects meta-analyses of prevalence for each risk factor, including estimation of overall, sex-specific, and HIV-transmission-group-specific prevalence. We compared prevalence in PLWHA with published prevalence estimates in US adults. The meta-analysis included 113 publications. Overall summary prevalence estimates were current smoking, 54% [95% confidence interval (CI) 49-59%] versus 20-23% in US adults; cervical high-risk HPV infection, 46% (95% CI 34-58%) versus 29% in US females; oral high-risk HPV infection, 16% (95% CI 10-23%) versus 4% in US adults; anal high-risk HPV infection (men who have sex with men), 68% (95% CI 57-79%), with no comparison estimate available; chronic HCV infection, 26% (95% CI 21-30%) versus 0.9% in US adults; and HBV infection, 5% (95% CI 4-5%) versus 0.3% in US adults. Overweight/obesity prevalence (53%; 95% CI 46-59%) was below that of US adults (68%). Meta-analysis of alcohol consumption prevalence was impeded by varying assessment methods. Overall, we observed considerable study heterogeneity in prevalence estimates. Prevalence of smoking and oncogenic virus infections continues to be extraordinarily high among PLWHA, indicating a vital need for risk factor reduction efforts.