-
Nephron. Clinical Practice 2010To describe how often a disease or another health event occurs in a population, different measures of disease frequency can be used. The prevalence reflects the number...
To describe how often a disease or another health event occurs in a population, different measures of disease frequency can be used. The prevalence reflects the number of existing cases of a disease. In contrast to the prevalence, the incidence reflects the number of new cases of disease and can be reported as a risk or as an incidence rate. Prevalence and incidence are used for different purposes and to answer different research questions. In this article, we discuss the different measures of disease frequency and we explain when to apply which measure.
Topics: Data Interpretation, Statistical; Epidemiologic Methods; Humans; Incidence; Prevalence; Terminology as Topic
PubMed: 20173345
DOI: 10.1159/000286345 -
Academic Emergency Medicine : Official... Sep 1996Careful consideration of statistical issues related to the choice of a sample size is critical for achieving meaningful results in research studies designed to evaluate... (Review)
Review
Careful consideration of statistical issues related to the choice of a sample size is critical for achieving meaningful results in research studies designed to evaluate diagnostic tests. When assessing the ability of a diagnostic test to screen for disease, the parameters sensitivity, specificity, and predictive values are of interest. Study sample size requirements can be calculated based on a clinically acceptable degree of precision, the hypothesized values of sensitivity and specificity, and the estimated prevalence of disease in the target population. The simple methods and tables in this paper guide the researcher when deciding how many subjects to sample in a study designed to estimate both the sensitivity and the specificity of a diagnostic test, given a specified precision and estimated disease prevalence.
Topics: Bias; Confidence Intervals; Data Interpretation, Statistical; Humans; Mass Screening; Prevalence; Reproducibility of Results; Research Design; Sampling Studies; Sensitivity and Specificity
PubMed: 8870764
DOI: 10.1111/j.1553-2712.1996.tb03538.x -
BMJ Open Mar 2022To assess the prevalence, risk factors and psychological impact of infertility among females. This review summarises the available evidence, effect estimates and... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
To assess the prevalence, risk factors and psychological impact of infertility among females. This review summarises the available evidence, effect estimates and strength of statistical associations between infertility and its risk factors.
STUDY DESIGN
Systematic review and meta-analysis.
DATA SOURCES
MEDLINE, CINAHL and ScienceDirect were searched through 23 January 2022.
ELIGIBILITY CRITERIA
The inclusion criteria involved studies that reported the psychological impact of infertility among women. We included cross-sectional, case-control and cohort designs, published in the English language, conducted in the community, and performed at health institution levels on prevalence, risk factors and psychological impact of infertility in women.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently extracted and assess the quality of data using the Joanna Briggs Institute Meta-Analysis. The outcomes were assessed with random-effects model and reported as the OR with 95% CI using the Review Manager software.
RESULTS
Thirty-two studies with low risk of bias involving 124 556 women were included. The findings indicated the overall pooled prevalence to be 46.25% and 51.5% for infertility and primary infertility, respectively. Smoking was significantly related to infertility, with the OR of 1.85 (95% CI 1.08 to 3.14) times higher than females who do not smoke. There was a statistical significance between infertility and psychological distress among females, with the OR of 1.63 (95% CI 1.24 to 2.13). A statistical significance was noted between depression and infertility among females, with the OR of 1.40 (95% CI 1.11 to 1.75) compared with those fertile.
CONCLUSIONS
The study results highlight an essential and increasing mental disorder among females associated with infertility and may be overlooked. Acknowledging the problem and providing positive, supportive measures to females with infertility ensure more positive outcomes during the therapeutic process. This review is limited by the differences in definitions, diagnostic cut points, study designs and source populations.
PROSPERO REGISTRATION NUMBER
CRD42021226414.
Topics: Cross-Sectional Studies; Female; Health Status; Humans; Infertility; Prevalence; Risk Factors
PubMed: 35354629
DOI: 10.1136/bmjopen-2021-057132 -
Journal of Cachexia, Sarcopenia and... Feb 2022Depression may be the most common cause of emotional distress later in life and can significantly reduce the quality of life in elderly individuals. Sarcopenia is a... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Depression may be the most common cause of emotional distress later in life and can significantly reduce the quality of life in elderly individuals. Sarcopenia is a syndrome characterized by the continuous loss of skeletal muscle mass and decreased strength and function. In recent years, many studies have shown a correlation between sarcopenia and depression. The present study aimed to investigate the prevalence of depression among individuals with sarcopenia and to ascertain whether sarcopenia is independently associated with depression.
METHODS
We systematically searched the PubMed, Embase, and Google Scholar databases for papers on sarcopenia published up to 31 August 2021. We reviewed the literature on the number of individuals with sarcopenia, the number of individuals with both sarcopenia and depression, and the odds ratio (OR) of sarcopenia to depression. Statistical analyses were performed using Meta-DiSc 1.4 software and Stata version 12.0.
RESULTS
Nineteen articles met the inclusion criteria for review: nine reported both prevalence and ORs, four described prevalence only, and six detailed the ORs only. Regarding prevalence, there were 1476 cases of sarcopenia and 364 of depression in the selected studies; the mean age of the patients was 75.5 years, and the overall prevalence of depression was 0.28 [95% confidence interval (CI): 0.21-0.36]. Significant heterogeneity was noted (P < 0.001; I = 92.2%). In the case of ORs, there were 16 869 subjects with a mean age of 73 years; the overall adjusted OR between sarcopenia and depression was 1.57 (95% CI: 1.32-1.86). Significant heterogeneity was noted in the adjusted ORs (P < 0.001; I = 75.1%).
CONCLUSIONS
The prevalence of depression in patients with sarcopenia was high relatively, and there was a correlation between sarcopenia and depression.
Topics: Aged; Depression; Humans; Odds Ratio; Prevalence; Quality of Life; Sarcopenia
PubMed: 34997702
DOI: 10.1002/jcsm.12908 -
Neurotherapeutics : the Journal of the... Jul 2012This article describes a comprehensive meta-analysis that was conducted to estimate the prevalence of attention-deficit/hyperactivity disorder (ADHD), as defined by the... (Meta-Analysis)
Meta-Analysis Review
This article describes a comprehensive meta-analysis that was conducted to estimate the prevalence of attention-deficit/hyperactivity disorder (ADHD), as defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV). A systematic literature review identified 86 studies of children and adolescents (N = 163,688 individuals) and 11 studies of adults (N = 14,112 individuals) that met inclusion criteria for the meta-analysis, more than half of which were published after the only previous meta-analysis of the prevalence of ADHD was completed. Although prevalence estimates reported by individual studies varied widely, pooled results suggest that the prevalence of DSM-IV ADHD is similar, whether ADHD is defined by parent ratings, teacher ratings, or a best estimate diagnostic procedure in children and adolescents (5.9-7.1 %), or by self-report measures in young adults (5.0 %). Analyses of diagnostic subtypes indicated that the predominantly inattentive type is the most common subtype in the population, but individuals with the combined type are more likely to be referred for clinical services. Additional research is needed to determine the etiology of the higher prevalence of ADHD in males than females and to clarify whether the prevalence of ADHD varies as a function of socioeconomic status or ethnicity. Finally, there were no significant prevalent differences between countries or regions of the world after controlling for differences in the diagnostic algorithms used to define ADHD. These results provide important support for the diagnostic validity of ADHD, and argue against the hypothesis that ADHD is a cultural construct that is restricted to the United States or any other specific culture.
Topics: Algorithms; Attention Deficit Disorder with Hyperactivity; Databases, Factual; Diagnostic and Statistical Manual of Mental Disorders; Humans; Prevalence
PubMed: 22976615
DOI: 10.1007/s13311-012-0135-8 -
PloS One 2020Vitiligo is an acquired depigmenting skin disease which is often accompanied by mental distress. There are numerous studies dedicated to local and global prevalence of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitiligo is an acquired depigmenting skin disease which is often accompanied by mental distress. There are numerous studies dedicated to local and global prevalence of depression in patients with vitiligo but anxiety has not been recognized as a major mental problem within named population. We aimed to evaluate the prevalence of anxiety among patients with vitiligo from different countries and to compare it with patients suffering from eczema, psoriasis, and acne.
METHODS
In November 2019, we conducted a systematic search for observational studies that examined the prevalence of anxiety in vitiligo patients. Fifteen studies comprising 1176 patients with vitiligo were included to our systematic review.
RESULTS
The general prevalence of anxiety among vitiligo patients was equal to 35.8%. Statistically significant difference in anxiety rates was found among female and male patients (47.32% vs 42.4%) (P = 0.03), but the clinical relevance of this issue remains arguable. In addition, the pooled odds ratio among vitiligo and non-vitiligo patients did not indicate a statistical significance among patients coming from different continents.
CONCLUSIONS
The pooled prevalence of anxiety among vitiligo patients worldwide was comparable to other severe skin disorders. This finding accentuates the necessity of anxiety awareness in management of patients with skin diseases.
Topics: Adult; Anxiety; Female; Humans; Male; Prevalence; Vitiligo
PubMed: 33170870
DOI: 10.1371/journal.pone.0241445 -
Danish Medical Journal Jan 2021The present prevalence of schizophrenia in Greenland is unknown. The aim of this study was to estimate the prevalence of schizophrenia in Nuuk and the rest of Greenland. (Observational Study)
Observational Study
INTRODUCTION
The present prevalence of schizophrenia in Greenland is unknown. The aim of this study was to estimate the prevalence of schizophrenia in Nuuk and the rest of Greenland.
METHODS
The study was designed as an observational, cross-sectional study based on statistical extractions and review of medical records for psychiatric patients in Greenland, aiming to determine the prevalence of schizophrenia.
RESULTS
The prevalence of schizophrenia was estimated to 1.0% in Nuuk and 0.7% in the rest of Greenland. More males than females were affected (male/female ratio 2.5). Poor socio-economic conditions were revealed for the majority of patients. Cardiovascular risk factors were monitored suboptimally.
CONCLUSIONS
An increased focus on socio-psychological rehabilitation and monitoring and control of cardiovascular risk factors is warranted.
FUNDING
The study was funded by a grant from The Greenlandic Research Council (Sundhedspuljen).
TRIAL REGISTRATION
not relevant.
Topics: Cross-Sectional Studies; Female; Greenland; Humans; Male; Prevalence; Schizophrenia
PubMed: 33543704
DOI: No ID Found -
Medicina (Kaunas, Lithuania) May 2021Sensitivity, which denotes the proportion of subjects correctly given a positive assignment out of all subjects who are actually positive for the outcome, indicates how... (Review)
Review
Sensitivity, which denotes the proportion of subjects correctly given a positive assignment out of all subjects who are actually positive for the outcome, indicates how well a test can classify subjects who truly have the outcome of interest. Specificity, which denotes the proportion of subjects correctly given a negative assignment out of all subjects who are actually negative for the outcome, indicates how well a test can classify subjects who truly do not have the outcome of interest. Positive predictive value reflects the proportion of subjects with a positive test result who truly have the outcome of interest. Negative predictive value reflects the proportion of subjects with a negative test result who truly do not have the outcome of interest. Sensitivity and specificity are inversely related, wherein one increases as the other decreases, but are generally considered stable for a given test, whereas positive and negative predictive values do inherently vary with pre-test probability (e.g., changes in population disease prevalence). This article will further detail the concepts of sensitivity, specificity, and predictive values using a recent real-world example from the medical literature.
Topics: Biomedical Research; Humans; Predictive Value of Tests; Prevalence; Sensitivity and Specificity
PubMed: 34065637
DOI: 10.3390/medicina57050503 -
Morbidity and Mortality Weekly Report.... Mar 2020Autism spectrum disorder (ASD).
PROBLEM/CONDITION
Autism spectrum disorder (ASD).
PERIOD COVERED
2016.
DESCRIPTION OF SYSTEM
The Autism and Developmental Disabilities Monitoring (ADDM) Network is an active surveillance program that provides estimates of the prevalence of ASD among children aged 8 years whose parents or guardians live in 11 ADDM Network sites in the United States (Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin). Surveillance is conducted in two phases. The first phase involves review and abstraction of comprehensive evaluations that were completed by medical and educational service providers in the community. In the second phase, experienced clinicians who systematically review all abstracted information determine ASD case status. The case definition is based on ASD criteria described in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
RESULTS
For 2016, across all 11 sites, ASD prevalence was 18.5 per 1,000 (one in 54) children aged 8 years, and ASD was 4.3 times as prevalent among boys as among girls. ASD prevalence varied by site, ranging from 13.1 (Colorado) to 31.4 (New Jersey). Prevalence estimates were approximately identical for non-Hispanic white (white), non-Hispanic black (black), and Asian/Pacific Islander children (18.5, 18.3, and 17.9, respectively) but lower for Hispanic children (15.4). Among children with ASD for whom data on intellectual or cognitive functioning were available, 33% were classified as having intellectual disability (intelligence quotient [IQ] ≤70); this percentage was higher among girls than boys (39% versus 32%) and among black and Hispanic than white children (47%, 36%, and 27%, respectively) [corrected]. Black children with ASD were less likely to have a first evaluation by age 36 months than were white children with ASD (40% versus 45%). The overall median age at earliest known ASD diagnosis (51 months) was similar by sex and racial and ethnic groups; however, black children with IQ ≤70 had a later median age at ASD diagnosis than white children with IQ ≤70 (48 months versus 42 months).
INTERPRETATION
The prevalence of ASD varied considerably across sites and was higher than previous estimates since 2014. Although no overall difference in ASD prevalence between black and white children aged 8 years was observed, the disparities for black children persisted in early evaluation and diagnosis of ASD. Hispanic children also continue to be identified as having ASD less frequently than white or black children.
PUBLIC HEALTH ACTION
These findings highlight the variability in the evaluation and detection of ASD across communities and between sociodemographic groups. Continued efforts are needed for early and equitable identification of ASD and timely enrollment in services.
Topics: Autism Spectrum Disorder; Child; Diagnostic and Statistical Manual of Mental Disorders; Female; Humans; Male; Population Surveillance; Prevalence; United States
PubMed: 32214087
DOI: 10.15585/mmwr.ss6904a1 -
Morbidity and Mortality Weekly Report.... Apr 2018Autism spectrum disorder (ASD).
PROBLEM/CONDITION
Autism spectrum disorder (ASD).
PERIOD COVERED
2014.
DESCRIPTION OF SYSTEM
The Autism and Developmental Disabilities Monitoring (ADDM) Network is an active surveillance system that provides estimates of the prevalence of autism spectrum disorder (ASD) among children aged 8 years whose parents or guardians reside within 11 ADDM sites in the United States (Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin). ADDM surveillance is conducted in two phases. The first phase involves review and abstraction of comprehensive evaluations that were completed by professional service providers in the community. Staff completing record review and abstraction receive extensive training and supervision and are evaluated according to strict reliability standards to certify effective initial training, identify ongoing training needs, and ensure adherence to the prescribed methodology. Record review and abstraction occurs in a variety of data sources ranging from general pediatric health clinics to specialized programs serving children with developmental disabilities. In addition, most of the ADDM sites also review records for children who have received special education services in public schools. In the second phase of the study, all abstracted information is reviewed systematically by experienced clinicians to determine ASD case status. A child is considered to meet the surveillance case definition for ASD if he or she displays behaviors, as described on one or more comprehensive evaluations completed by community-based professional providers, consistent with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) diagnostic criteria for autistic disorder; pervasive developmental disorder-not otherwise specified (PDD-NOS, including atypical autism); or Asperger disorder. This report provides updated ASD prevalence estimates for children aged 8 years during the 2014 surveillance year, on the basis of DSM-IV-TR criteria, and describes characteristics of the population of children with ASD. In 2013, the American Psychiatric Association published the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), which made considerable changes to ASD diagnostic criteria. The change in ASD diagnostic criteria might influence ADDM ASD prevalence estimates; therefore, most (85%) of the records used to determine prevalence estimates based on DSM-IV-TR criteria underwent additional review under a newly operationalized surveillance case definition for ASD consistent with the DSM-5 diagnostic criteria. Children meeting this new surveillance case definition could qualify on the basis of one or both of the following criteria, as documented in abstracted comprehensive evaluations: 1) behaviors consistent with the DSM-5 diagnostic features; and/or 2) an ASD diagnosis, whether based on DSM-IV-TR or DSM-5 diagnostic criteria. Stratified comparisons of the number of children meeting either of these two case definitions also are reported.
RESULTS
For 2014, the overall prevalence of ASD among the 11 ADDM sites was 16.8 per 1,000 (one in 59) children aged 8 years. Overall ASD prevalence estimates varied among sites, from 13.1-29.3 per 1,000 children aged 8 years. ASD prevalence estimates also varied by sex and race/ethnicity. Males were four times more likely than females to be identified with ASD. Prevalence estimates were higher for non-Hispanic white (henceforth, white) children compared with non-Hispanic black (henceforth, black) children, and both groups were more likely to be identified with ASD compared with Hispanic children. Among the nine sites with sufficient data on intellectual ability, 31% of children with ASD were classified in the range of intellectual disability (intelligence quotient [IQ] <70), 25% were in the borderline range (IQ 71-85), and 44% had IQ scores in the average to above average range (i.e., IQ >85). The distribution of intellectual ability varied by sex and race/ethnicity. Although mention of developmental concerns by age 36 months was documented for 85% of children with ASD, only 42% had a comprehensive evaluation on record by age 36 months. The median age of earliest known ASD diagnosis was 52 months and did not differ significantly by sex or race/ethnicity. For the targeted comparison of DSM-IV-TR and DSM-5 results, the number and characteristics of children meeting the newly operationalized DSM-5 case definition for ASD were similar to those meeting the DSM-IV-TR case definition, with DSM-IV-TR case counts exceeding DSM-5 counts by less than 5% and approximately 86% overlap between the two case definitions (kappa = 0.85).
INTERPRETATION
Findings from the ADDM Network, on the basis of 2014 data reported from 11 sites, provide updated population-based estimates of the prevalence of ASD among children aged 8 years in multiple communities in the United States. The overall ASD prevalence estimate of 16.8 per 1,000 children aged 8 years in 2014 is higher than previously reported estimates from the ADDM Network. Because the ADDM sites do not provide a representative sample of the entire United States, the combined prevalence estimates presented in this report cannot be generalized to all children aged 8 years in the United States. Consistent with reports from previous ADDM surveillance years, findings from 2014 were marked by variation in ASD prevalence when stratified by geographic area, sex, and level of intellectual ability. Differences in prevalence estimates between black and white children have diminished in most sites, but remained notable for Hispanic children. For 2014, results from application of the DSM-IV-TR and DSM-5 case definitions were similar, overall and when stratified by sex, race/ethnicity, DSM-IV-TR diagnostic subtype, or level of intellectual ability.
PUBLIC HEALTH ACTION
Beginning with surveillance year 2016, the DSM-5 case definition will serve as the basis for ADDM estimates of ASD prevalence in future surveillance reports. Although the DSM-IV-TR case definition will eventually be phased out, it will be applied in a limited geographic area to offer additional data for comparison. Future analyses will examine trends in the continued use of DSM-IV-TR diagnoses, such as autistic disorder, PDD-NOS, and Asperger disorder in health and education records, documentation of symptoms consistent with DSM-5 terminology, and how these trends might influence estimates of ASD prevalence over time. The latest findings from the ADDM Network provide evidence that the prevalence of ASD is higher than previously reported estimates and continues to vary among certain racial/ethnic groups and communities. With prevalence of ASD ranging from 13.1 to 29.3 per 1,000 children aged 8 years in different communities throughout the United States, the need for behavioral, educational, residential, and occupational services remains high, as does the need for increased research on both genetic and nongenetic risk factors for ASD.
Topics: Autism Spectrum Disorder; Child; Female; Humans; Male; Population Surveillance; Prevalence; United States
PubMed: 29701730
DOI: 10.15585/mmwr.ss6706a1