A tool for assessing the usefulness of prevalence studies done for surveillance purposes: the example of hypertension

Tool to assess risk of bias in studies estimating the prevalence of mental health disorders (RoB-PrevMH)

OBJECTIVE

There is no standard tool for assessing risk of bias (RoB) in prevalence studies. For the purposes of a living systematic review during the COVID-19 pandemic, we developed a tool to evaluate RoB in studies measuring the prevalence of mental health disorders (RoB-PrevMH) and tested inter-rater reliability.

METHODS

We decided on items and signalling questions to include in RoB-PrevMH through iterative discussions. We tested the reliability of assessments by different users with two sets of prevalence studies. The first set included a random sample of 50 studies from our living systematic review. The second set included 33 studies from a systematic review of the prevalence of post-traumatic stress disorders, major depression and generalised anxiety disorder. We assessed the inter-rater agreement by calculating the proportion of agreement and Kappa statistic for each item.

RESULTS

RoB-PrevMH consists of three items that address selection bias and information bias. Introductory and signalling questions guide the application of the tool to the review question. The inter-rater agreement for the three items was 83%, 90% and 93%. The weighted kappa scores were 0.63 (95% CI 0.54 to 0.73), 0.71 (95% CI 0.67 to 0.85) and 0.32 (95% CI -0.04 to 0.63), respectively.

CONCLUSIONS

RoB-PrevMH is a brief, user-friendly and adaptable tool for assessing RoB in studies on prevalence of mental health disorders. Initial results for inter-rater agreement were fair to substantial. The tool's validity, reliability and applicability should be assessed in future projects.

[User satisfaction of the health services: A methodological quality checklist]

OBJECTIVE

Describe the methodological characteristics of observational studies in the field of evaluation of user satisfaction of PHC services at the regional level by applying a new checklist generated by the authors.

METHODS

A cross-sectional descriptive study, carried out between April and August 2017, included 17 publications on satisfaction in Primary Health Care published in Latin American journals.

RESULTS

In the classification according to the proposed checklist, both reviewers agreed on items such as: no inclusion of ethical aspects (10/17; 58,8%), no declaration of population/universe (6/17; 35,3%); does not comply with the initially declared objective (5/17; 29,4%), does not declare period of study completion (4/17; 25,3%) publications, does not declare study type (3/17; 17,6%). Value of the Spearman RHO correlation of qualified items between both reviewers (r=0,653).

CONCLUSIONS

The methodological approaches of the characterized publications are descriptive, cross-sectional with the absence of important items or methodological characteristics in almost all cases, which makes methodological reproducibility difficult; with few publications whose findings are reproducible. The proposed list proved to be a practical tool for methodological verification of observational studies on user satisfaction of health services in Primary Health Care.

A tool to assess risk of bias in studies estimating the prevalence of mental health disorders (RoB-PrevMH)

Objective

Biases affect how certain we are about the available evidence, however no standard tool for assessing the risk of bias (RoB) in prevalence studies exists. For the purposes of a living systematic review on prevalence of mental health disorders during the COVID-19 pandemic, we developed a RoB tool to evaluate prevalence studies in mental health (RoB-PrevMH) and tested interrater reliability.

Methods

We reviewed existing RoB tools for prevalence studies until September 2020, to develop a tool for prevalence studies in mental health. We tested the reliability of assessments by different users of RoB-PrevMH in 83 studies stemming from two systematic reviews of prevalence studies in mental health. We assessed the interrater agreement by calculating the proportion of agreement and Kappa statistic for each item.

Results

RoB-PrevMH consists of three items that address selection bias and information bias. Introductory and signaling questions guide the application of the tool to the review question. The interrater agreement for the three items was 83%, 90% and 93%. The weighted kappa was 0.63 (95% CI 0.54 to 0.73), 0.71 (95% CI 0.67 to 0.85) and 0.32 (95% CI -0.04 to -0.63), respectively.

Conclusions

We developed a brief, user friendly, and adaptable tool for assessing RoB in studies on prevalence of mental health disorders. Initial results for interrater agreement were fair to substantial. The tool's validity, reliability, and applicability should be assessed in future projects.

Birth prevalence of phenylalanine hydroxylase deficiency: a systematic literature review and meta-analysis

BACKGROUND

Phenylalanine hydroxylase (PAH) deficiency is an autosomal recessive disorder that results in elevated concentrations of phenylalanine (Phe) in the blood. If left untreated, the accumulation of Phe can result in profound neurocognitive disability. The objective of this systematic literature review and meta-analysis was to estimate the global birth prevalence of PAH deficiency from newborn screening studies and to estimate regional differences, overall and for various clinically relevant Phe cutoff values used in confirmatory testing.

METHODS

The protocol for this literature review was registered with PROSPERO (International prospective register of systematic reviews). Pubmed and Embase database searches were used to identify studies that reported the birth prevalence of PAH deficiency. Only studies including numeric birth prevalence reports of confirmed PAH deficiency were included.

RESULTS

From the 85 publications included in the review, 238 birth prevalence estimates were extracted. After excluding prevalence estimates that did not meet quality assessment criteria or because of temporal and regional overlap, estimates from 45 publications were included in the meta-analysis. The global birth prevalence of PAH deficiency, estimated by weighting regional birth prevalences relative to their share of the population of all regions included in the study, was 0.64 (95% confidence interval [CI] 0.53-0.75) per 10,000 births and ranged from 0.03 (95% CI 0.02-0.05) per 10,000 births in Southeast Asia to 1.18 (95% CI 0.64-1.87) per 10,000 births in the Middle East/North Africa. Regionally weighted global birth prevalences per 10,000 births by confirmatory test Phe cutoff values were 0.96 (95% CI 0.50-1.42) for the Phe cutoff value of 360 ± 100 µmol/L; 0.50 (95% CI 0.37-0.64) for the Phe cutoff value of 600 ± 100 µmol/L; and 0.30 (95% CI 0.20-0.40) for the Phe cutoff value of 1200 ± 200 µmol/L.

CONCLUSIONS

Substantial regional variation in the birth prevalence of PAH deficiency was observed in this systematic literature review and meta-analysis of published evidence from newborn screening. The precision of the prevalence estimates is limited by relatively small sample sizes, despite widespread and longstanding newborn screening in much of the world.

Quality assessment of prevalence studies: a systematic review

OBJECTIVES

The objective of the study is to identify items and domains applicable for the quality assessment of prevalence studies.

STUDY DESIGN AND SETTING

We searched databases and the gray literature to identify tools or guides about the quality assessment of prevalence studies. After study selection, we abstracted questions applicable for prevalence studies and classified into at least one of the following domains: 'population and setting', 'condition measurement', 'statistics', and 'other'. PROSPERO registration:CRD42018088437.

RESULTS

We included 30 tools: eight (26.7%) specifically designed to appraise prevalence studies and 22 (73.3%) adaptable for this purpose. We identified 12 unique items in the domain "population and setting", 16 in the domain "condition measurement", and 14 in the domain "statistics". Of those, 25 (59.5%) were identified in the eight specific tools. Regarding the domain "other", we identified 77 unique items, mainly related to manuscript writing and reporting (n = 48, 62.3%); of those, 24 (31.2%) were identified in the eight specific tools and 53 (68.8%) in the additional 22 nonspecific tools.

CONCLUSION

We provide a comprehensive set of items classified by domains that can guide the appraisal of prevalence studies, conduction of primary prevalence studies, and update or development of tools to evaluate prevalence studies.

Brucellosis in food-producing animals in Mosul, Iraq: A systematic review and meta-analysis

Brucellosis is an endemic disease in food-producing animals in Mosul, Iraq. The objectives of the study reported here were: (i) to identify and assess the evidence and knowledge gaps in published studies that have examined brucellosis in different food-producing animals in Mosul, Iraq; using systematic review approach, and (ii) to quantify the seroprevalence of brucellosis in the city using meta-analysis approach. Google Scholar was used as a search engine to track pertinent peer-reviewed research reports. The search was conducted on November 24, 2019. Keywords used were: brucella, animal, Mosul, Iraq. Peer-reviewed published studies, MSc theses, and PhD dissertations written in Arabic or English were included. Duplicate records were removed, and the screening process was conducted at three levels: titles, abstracts, and full-text articles. Identified studies that have reported the seroprevalence of brucellosis were included in a meta-analysis to calculate an overall prevalence. A total of 214 records were initially identified. Seventeen research reports were added from personal contact and qualified articles’ references list. Thirty six articles were qualified for review after removing 35 duplicate records, 155 titles, 11 abstracts, and 5 full text articles. Seventeen studies reported the prevalence of brucellosis, 11 studies assessed different serological tests for diagnosis of brucellosis, 9 studies isolated Brucella spp. from animal specimens and/or animal products, and 4 studies assessed vaccination procedures against brucellosis. The overall seroprevalence of brucellosis in food-producing animals in Mosul over a period of 40 years was 14.14%, including 14.46% for sheep, 12.99% for goats, 11.69% for cattle, and 22.64% for buffalo. The study concluded that the disease is evident in the city with increasing trends over the years, buffalo shows high seroprevalence, the degree of agreement of Rose-Bengal test as a screening test is fair compared to more accurate serological tests such as ELISA; and the disease constitutes a public health concern in the city. Additional studies are important to identify the overlooked predisposing factors, estimate the abortion rate attributable to brucellosis in food-producing animals, and evaluate efficacy of vaccination programs in reducing the prevalence of brucellosis and/or abortion rate.

Prevalence of psychological symptoms among adults with sickle cell disease in Korle-Bu Teaching Hospital, Ghana

BACKGROUND

Previous research revealed high prevalence of psychological symptoms among sickle cell disease (SCD) patients in the West and Europe. In some Black SCD populations such as Nigeria and Jamaica, anxiety and depression had low prevalence rates compared to Europe. With difficulty locating research data on the prevalence of psychological symptoms in Ghana, this study aimed at exploring psychological symptoms among adults with SCD in a Teaching Hospital in Accra, Ghana.

METHODS

Two hundred and one participants (males 102 and females 99) who were HbSS (n = 131) and HbSC (n = 70), aged 18 years and above were purposively recruited. Using the Brief Symptom Inventory (BSI) in a cross-sectional survey, the research answered questions about the prevalence of psychological symptoms. It also examined gender and genotype differences in psychological symptoms scores.

RESULTS

Results indicated that adults with SCD had non-distress psychological symptoms scores. Although paranoid ideation as a psychological symptom indicated "a little bit" score, its prevalence was only 1 %. The prevalence of psychological symptoms as indexed by the Positive Symptom Total (PST) was 10 %. Anxiety, hostility, and depression were psychological symptoms with low scores. Furthermore, except psychoticism scores, males did not differ significantly from females in other psychological symptoms. On the contrary, HbSS participants differed significantly, reporting more psychological symptoms than their HbSC counterparts.

CONCLUSIONS

The study concluded that there was low prevalence of psychological symptoms among adults with SCD in this Ghanaian study. Although psychological symptoms distress scores were not observed among study participants at this time, females differed significantly by experiencing more psychoticism symptoms than males. HbSS participants also differed significantly by experiencing more depression, phobic anxiety, paranoid ideation, psychoticism, and additional symptoms such as poor appetite, trouble falling asleep, thoughts of dying, and feeling guilty, than their HbSC counterparts. Implications for further study and clinical practice were discussed.

Prevalence of hypertension and associated factors in an indigenous community of central Brazil: a population-based study

Objective

The aim of the present study was to assess the prevalence of hypertension and cardiovascular risk factors among the native indigenous of Jaguapiru village in Dourados, Mato Grosso do Sul, Brazil.

Method

A cross-sectional, population-based study was conducted with adult indigenous aged 18 years or more. The subjects' blood pressure was measured twice, and the mean of the two measurements was calculated. Body weight, height, capillary blood glucose and waist circumference were measured. Pregnant women, individuals using glucocorticoids, and non-indigenous villagers and their offspring were excluded. Multivariate regression analyses were conducted on the socio-demographic and clinical independent variables. Interactions between independent variables were also tested.

Results

We included 1,608 native indigenous eligible to the research. The prevalence of hypertension was 29.5% (95% CI: 27–31.5), with no significant difference between the genders. For both men and women, diastolic hypertension was more common than systolic hypertension. The prevalence of hypertension was higher among obese, diabetic, and older participants, as well as those who consumed alcohol, had a lower educational level, or had a family history of hypertension. There was no association between hypertension and tobacco smoking or family income.

Conclusion

Hypertension among the indigenous from Jaguapiru village was similar to the prevalence in the Brazilians, but may have a more negative effect in such disadvantaged population. The associated factors we found can help drawing prevention policies.

Chlamydia prevalence in the general population: is there a sex difference? a systematic review

Background

The focus of Chlamydia trachomatis screening and testing lies more on women than on men. The study aim was to establish by systematic review the prevalence of urogenital Chlamydia trachomatis infection in men and women in the general population.

Methods

Electronic databases and reference lists were searched from 2000 to 2013 using the key words “Chlamydia trachomatis”, “population-based study” and “disease prevalence”. Reference lists were checked. Studies were included in the analysis if Chlamydia trachomatis prevalence was reported for both men and women in a population-based study. Prevalence rates for men and women were described as well as highest prevalence rate by age and sex. The difference in prevalence between the sexes in each study was calculated.

Results

Twenty-five studies met the inclusion criteria and quality assessment for the review. In nine of the twenty-five studies there was a statistically significant sex difference in the chlamydia prevalence. In all nine studies the prevalence of chlamydia was higher in women than in men. The prevalence for women varied from 1.1% to 10.6% and for men from 0.1% to 12.1%. The average chlamydia prevalence is highly variable between countries. The highest prevalence of chlamydia occurred predominantly in younger age groups (< 25 years). The absence of symptoms in population-based urogenital chlamydia infection is common in men and women (mean 88.5% versus 68.3%).

Conclusions

The urogenital chlamydia trachomatis prevalence in the general population is more similar than dissimilar for men and women. A modest sex difference is apparent. The prevalence rates can be used to inform chlamydia screening strategies in general practice.

Caries and periodontal disease in cancer survivors

DATA SOURCES

PubMed and EMBASE were searched for articles published between 1 January 1990 and 31 December 2008.

STUDY SELECTION

Eligible studies were those that included dental caries and periodontal disease and pre-cancer dental clearance protocols in cancer patients undergoing head and neck radiotherapy, chemotherapy or combined treatment modalities. Rather than any study inclusion criteria this review had a number of exclusion criteria instead: systematic and non-systematic reviews; microbiology studies; growth and development studies; organ transplant studies; studies eliciting dental complications through questionnaires, studies reporting data from previous publications; phase I and II studies; opinion papers and case reports; articles published before 1990. All reports also had to be in English.

DATA EXTRACTION AND SYNTHESIS

Each article was reviewed by two authors independently with pilot-tested data collection forms. No quality assessment was pre-specified.

RESULTS

Sixty-four articles were included. Forty-six of these were observational (24 cohort, eight case control, 14 cross-sectional), and 18 were interventional studies. It is unclear how many participants this included. A weighted prevalence of caries was reported but it is unclear how the weighting was calculated. Overall the weighted prevalence was 28.1%. The overall DMFT for patients who were post-antineoplastic therapy was 9.19 (SD, 7.98; n=457). The overall plaque index for patients who were post-antineoplastic therapy was 1.38 (SD, 0.25; n=189).

CONCLUSIONS

Patients who were post-radiotherapy had the highest DMFT compared to those who were post-chemotherapy and healthy controls.

Development and validation of a microsimulation economic model to evaluate the disease burden associated with smoking and the cost-effectiveness of tobacco control interventions in Latin America

OBJECTIVE

To describe the development and validation of a health economic model (HEM) to address the tobacco disease burden and the cost-effectiveness of smoking cessation interventions (SCI) in seven Latin American countries.

METHODS

The preparatory stage included the organization of the research network, analysis of availability of epidemiologic data, and a survey to health decision makers to explore country-specific information needs. The development stage involved the harmonization of a methodology to retrieve local relevant parameters and develop the model structure. Calibration and validation was performed using a selected country dataset (Argentina 2005). Predicted event rates were compared to the published rates used as model inputs. External validation was undertaken against epidemiologic studies that were not used to provide input data.

RESULTS

Sixty-eight decision makers were surveyed. A microsimulation HEM was built considering the availability and quality of epidemiologic data and relevant outcomes conceived to suit the identified information needs of decision makers. It considers all tobacco-related diseases (i.e., heart, cerebrovascular and chronic obstructive pulmonary disease, pneumonia/influenza, lung cancer, and nine other neoplasms) and can incorporate individual- and population-level interventions. The calibrated model showed all simulated event rates falling within ± 10% of the sources (-9%-+5%). External validation showed a high correlation between published data and model results.

CONCLUSIONS

This evidence-based, internally and externally valid HEM for the assessment of the effects of smoking and SCIs incorporates a broad spectrum of tobacco related diseases, SCI, and benefit measures. It could be a useful policy-making tool to estimate tobacco burden and cost-effectiveness of SCI.

A new instrument for assessing the quality of studies on prevalence

There are numerous scientific articles of studies on the prevalence of disorders with non-standardised examination and diagnostic protocols. Because their quality is heterogeneous, a new instrument has been developed for the assessment of such studies. The new instrument is based mainly on statistical criteria. The points assigned for each of the main criteria according to the information gained from each paper are summed up to form a Total Quality Score (TQS). The interrater reliability of the instrument was tested by employing Kappa and Interrater Correlation Coefficient (ICC) statistics. The latter was assessed on the results of three independent investigators. The new quality instrument appeared to be easy to use, and the instructions were comprehensible. The ICC((2,1)) for the TQS ranged between 0.94 and 1.00 indicating almost perfect agreement between the investigators. The reliability of the new instrument enables its use for scientific review purposes. In this way, its validity will also be tested. The instrument could be adopted for assessment of scientific articles of studies on the prevalence of disorders in many, similar, scientific areas.

[Public health surveillance and role of administrative data]

BACKGROUND

Public health surveillance constitutes an important activity since it helps in identifying health needs through data collection, and contributes to decision making and actions by analyzing and interpreting data and communicating key results.

METHODS

This paper presents a discussion on the concept of public health surveillance, its objectives and its historical evolution. It deals with the importance of surveillance systems while describing their components and challenges. In addition, the authors point out the importance of administrative data as a relevant source for the surveillance of public health problems, particularly chronic diseases and risk factors.

RESULTS

This theoretical discussion leads to the proposal of a conceptual model for surveillance systems, which integrates implementation and evaluation.

CONCLUSION

This article provides a summary of the concept of public health surveillance and underlines the general aspects to be considered by the managers of surveillance systems. It also discusses the use of administrative data for surveillance.