Systematic Review Of Prospective Studies Research Articles

Predicting the development of schizophrenia in high-risk populations: Systematic review of the predictive validity of prodromal criteria

There is a great deal of debate on the usefulness and accuracy of prodromal criteria in predicting schizophrenia. The risk of treating people who screen false positive with medication is considerable. Yet intervening during the prodromal stage of illness may reduce the burden caused by schizophrenia. To draw together the evidence base for the predictive validity of prodromal criteria in identifying individuals at high risk of developing schizophrenia. We conducted a systematic review of prospective studies investigating the predictive validity of prodromal criteria in schizophrenia. Our study found two main criteria, ultra-high-risk criteria and basic-symptoms criteria, used in studies investigating the predictive validity of prodromal symptoms. The sensitivity and specificity of ultra-high-risk criteria was 0.81 (95% CI 0.76-0.85) and 0.67 (95% CI 0.64-0.70) respectively and for basic-symptoms criteria sensitivity and specificity was 0.97 (95% CI 0.91-1.00) and 0.59 (95% CI 0.48-0.70) respectively. Both ultra-high-risk criteria and basic-symptoms criteria are useful in predicting the development of schizophrenia among high-risk populations.

Association Between Vitamin D and Risk of Colorectal Cancer: A Systematic Review of Prospective Studies

To conduct a systematic review of prospective studies assessing the association of vitamin D intake or blood levels of 25-hydroxyvitamin D [25(OH)D] with the risk of colorectal cancer using meta-analysis. Relevant studies were identified by a search of MEDLINE and EMBASE databases before October 2010 with no restrictions. We included prospective studies that reported relative risk (RR) estimates with 95% CIs for the association between vitamin D intake or blood 25(OH)D levels and the risk of colorectal, colon, or rectal cancer. Approximately 1,000,000 participants from several countries were included in this analysis. Nine studies on vitamin D intake and nine studies on blood 25(OH)D levels were included in the meta-analysis. The pooled RRs of colorectal cancer for the highest versus lowest categories of vitamin D intake and blood 25(OH)D levels were 0.88 (95% CI, 0.80 to 0.96) and 0.67 (95% CI, 0.54 to 0.80), respectively. There was no heterogeneity among studies of vitamin D intake (P = .19) or among studies of blood 25(OH)D levels (P = .96). A 10 ng/mL increment in blood 25(OH)D level conferred an RR of 0.74 (95% CI, 0.63 to 0.89). Vitamin D intake and blood 25(OH)D levels were inversely associated with the risk of colorectal cancer in this meta-analysis.

Breastfeeding of Newborns by Mothers Carrying Hepatitis B Virus

To perform a systematic review of prospective studies to confirm the role of breastfeeding in mother-to-child transmission (MTCT) of hepatitis B virus (HBV). A database was constructed from MEDLINE, EMBASE, Cochrane Library, National Science Digital Library, and China Biological Medicine Database and through contact with experts in this field from January 1, 1990, to August 31, 2010. All studies were peer reviewed and met the preset inclusion standards. Breastfeeding. Data regarding HBV intrauterine infection, MTCT, maternal blood and breast milk infectiousness, infant immunoprophylaxis methods and response, and adverse events. The Mantel-Haenszel fixed-effects model was used for all analyses using odds ratios and 95% confidence intervals. Ten qualified studies were included. All were clinical controlled trials, involving 751 infants in the breastfeeding group and 873 infants in the nonbreastfeeding group. As indicated by infant peripheral blood hepatitis B surface antigen or HBV DNA positivity at age 6 to 12 months, the odds ratio of MTCT of HBV in the breastfeeding group compared with that in the nonbreastfeeding group was 0.86 (95% confidence interval, 0.51-1.45) (from 8 clinical controlled trials, P = .56; I(2) = 0%, P = .99). As indicated by infant peripheral blood hepatitis B surface antibody positivity at age 6 to 12 months, the odds ratio of development of hepatitis B surface antibodies in the breastfeeding group compared with that in the nonbreastfeeding group was 0.98 (95% confidence interval, 0.69-1.40) (from 8 clinical controlled trials, P = .93; I(2) = 0%, P = .99). No adverse events or complications during breastfeeding were observed. Breastfeeding after proper immunoprophylaxis did not contribute to MTCT transmission of HBV.

Objectively measured physical activity and obesity prevention in children, adolescents and adults: a systematic review of prospective studies

This study aimed at synthesizing the prospective associations between measured physical activity (PA) and change in adiposity in children, adolescents and adults following from two previous reviews. Search terms were adapted and a systematic literature search was conducted (January 2000-September 2008) and later updated (up to October 2009), considering observational and intervention studies of weight gain that measured both PA and body composition. Sixteen observational studies (six comprising adults) and five trials (one comprising adults) were eligible. For consistency, whenever possible either baseline PA energy expenditure or accelerometer output (counts min(-1) ) and change in per cent body fat were the extracted exposure and outcome measures. Results of observational studies suggest that PA is not strongly prospectively related with adiposity: five studies on children and three on adults reported no association between baseline PA and change in adiposity, one study found a weak positive association and the other studies observed a weak negative association. Negative associations were more frequently observed in studies that analysed the association between change in the exposure and outcome. Intervention studies show generally no effect on either PA or adiposity. In conclusion, despite the well-established health benefits of PA, it may not be a key determinant of excessive gain in adiposity.

Relationship between young peoples' sedentary behaviour and biomedical health indicators: a systematic review of prospective studies

The aim of this systematic review was to describe the prospective relationship between childhood sedentary behaviour and health indicators. We identified prospective studies from searches in PubMed, EMBASE, PsycInfo and Cochrane, from January 1989 through April 2010. Two reviewers independently screened the titles and abstracts for eligibility, rated the methodological quality of the studies, and extracted data. We identified 31 papers, examining 27 different cohorts. The quality score of the studies ranged from 38 to 88%. Nine studies were scored as high quality. According to the best evidence synthesis we found insufficient evidence for a longitudinal positive relationship between 'sedentary time'- mainly TV viewing - and body mass index (BMI) and more specific indicators of fat mass. One high quality and two low quality studies found a significant inverse relationship between sedentary time - mainly TV viewing - and aerobic fitness, leading to moderate evidence for this inverse relationship. There was insufficient evidence for a longitudinal relationship between sedentary time and blood pressure, blood lipids or bone mass. Our systematic review suggests that there is moderate evidence for a longitudinal inverse relationship between screen time and aerobic fitness during childhood. Thus there is evidence to limit screen time in young people in order to prevent low levels of fitness. The possible detrimental health effects of prolonged or excessive sitting on other health indicators needs further study.

Seizure recurrence after antiepileptic drug withdrawal and the implications for driving: further results from the MRC Antiepileptic Drug Withdrawal Study and a systematic review

BackgroundIn the UK, patients with epilepsy in remission, who withdraw antiepileptic drug (AED) treatment, are advised not to drive during withdrawal and for 6 months thereafter, assuming the risk of...

Prevention of Type 2 Diabetes by Dietary Patterns: A Systematic Review of Prospective Studies and Meta-Analysis

Lifestyle intervention may reduce the risk of type 2 diabetes. The aim of this study was to investigate the role of dietary patterns in the prevention of type 2 diabetes. We did an electronic search through November 30, 2009, for prospective studies that evaluated the role of dietary patterns in type 2 diabetes prevention. Ten large prospective studies were identified, comprising more than 190,000 subjects free of diabetes at baseline, followed for a time ranging from 2 to 23 years, and 8,932 cases of incident diabetes. All ten studies showed consistent results: Relative risk reduction of type 2 diabetes ranged from 83% to 15%. Overall, adherence to a healthy dietary pattern was associated with reduced risk of developing type 2 diabetes: Combined mean difference = -0.39, 95% confidence interval (CI) -0.54 to -0.24. The reduced risk of developing type 2 diabetes was still present after sensitivity analysis (-0.34, 95% CI -0.44 to -0.24). Dietary patterns characterized by high consumption of fruit and vegetables, whole grains, fish, and poultry, and by decreased consumption of red meat, processed foods, sugar-sweetened beverages, and starchy foods may retard the progression of type 2 diabetes. Healthy diets can help people to live more years without type 2 diabetes.

A systematic review of prospective studies on attention problems and academic achievement

Our aim was to provide an overview of prospective studies that have addressed the association between attention problems (AP, i.e. symptoms of hyperactivity and inattentiveness) and academic achievement (AA). We conducted a systematic search in the literature. Normal population studies and clinical studies were included. The methodological quality of each study was evaluated by objective criteria. A best evidence synthesis was used to determine the strengths of the association. Sixteen studies were included. We found convincing evidence for a negative association between AP and AA. After controlling for intelligence, comorbidity, and socioeconomic status (SES), the association between the hyperactive symptoms of AP and AA was non-significant in two studies. Children with AP are at risk for lower AA and subsequent adverse outcomes later in life. Interventions in affected children should focus on their behavioural and educational development.

Systematic review and meta-analysis of the efficacy of appropriate empiric antibiotic therapy for sepsis.

Quantifying the benefit of early antibiotic treatment is crucial for decision making and can be assessed only in observational studies. We performed a systematic review of prospective studies reporting the effect of appropriate empirical antibiotic treatment on all-cause mortality among adult inpatients with sepsis. Two reviewers independently extracted data. Risk of bias was assessed using the Newcastle-Ottawa score. We calculated unadjusted odds ratios (ORs) with 95% confidence intervals for each study and extracted adjusted ORs, with variance, methods, and covariates being used for adjustment. ORs were pooled using random-effects meta-analysis. We examined the effects of methodological and clinical confounders on results through subgroup analysis or mixed-effect meta-regression. Seventy studies were included, of which 48 provided an adjusted OR for inappropriate empirical antibiotic treatment. Inappropriate empirical antibiotic treatment was associated with significantly higher mortality in the unadjusted and adjusted comparisons, with considerable heterogeneity occurring in both analyses (I(2) > 70%). Study design, time of mortality assessment, the reporting methods of the multivariable models, and the covariates used for adjustment were significantly associated with effect size. Septic shock was the only clinical variable significantly affecting results (it was associated with higher ORs). Studies adjusting for background conditions and sepsis severity reported a pooled adjusted OR of 1.60 (95% confidence interval = 1.37 to 1.86; 26 studies; number needed to treat to prevent one fatal outcome, 10 patients [95% confidence interval = 8 to 15]; I(2) = 46.3%) given 34% mortality with inappropriate empirical treatment. Appropriate empirical antibiotic treatment is associated with a significant reduction in all-cause mortality. However, the methods used in the observational studies significantly affect the effect size reported. Methods of observational studies assessing the effects of antibiotic treatment should be improved and standardized.

Frequency of Nonodontogenic Pain after Endodontic Therapy: A Systematic Review and Meta-Analysis

Introduction Little is known about ill-defined pain that persists after endodontic procedures, including an estimate of the problem's magnitude. We conducted a systematic review of prospective studies that reported the frequency of nonodontogenic pain in patients who had undergone endodontic procedures. Methods Nonodontogenic pain was defined as dentoalveolar pain present for 6 months or more after endodontic treatment without evidence of dental pathology. Endodontic procedures reviewed were nonsurgical root canal treatment, retreatment, and surgical root canal treatment. Studies were searched in four databases electronically, complemented by hand searching. A summary estimate of nonodontogenic tooth pain frequency was derived using random-effects meta-analysis. Results Of 770 articles retrieved and reviewed, 10 met inclusion criteria, and nine had data on both odontogenic and nonodontogenic causes of pain. A total of 3,343 teeth were enrolled within the included studies and 1,125 had follow-up information regarding pain status. We identified 48 teeth with nonodontogenic pain and estimated a 3.4% (95% confidence interval, 1.4%-5.5%) frequency of occurrence. In nine articles containing data regarding both odontogenic and nonodontogenic causes of tooth pain, 56% (44/78) of all cases were thought to have a nonodontogenic cause. Conclusions Nonodontogenic pain is not an uncommon outcome after root canal therapy and may represent half of all cases of persistent tooth pain. These findings have implications for the diagnosis and treatment of painful teeth that were previously root canal treated because therapy directed at the tooth in question would not be expected to resolve nonodontogenic pain.

Magnetic resonance (MR) colonography in the detection of colorectal lesions: a systematic review of prospective studies

ObjectiveTo determine the diagnostic accuracy of MR-colonography for the detection of colorectal lesions.MethodsA comprehensive literature search was performed for comparative MR-colonography studies, published between May 1997 and February 2009, using the MEDLINE, EMBASE and Cochrane databases. We included studies if MR-colonography findings were prospectively compared with conventional colonoscopy in (a)symptomatic patients. Two reviewers independently extracted study design characteristics and data for summarising sensitivity and specificity. Heterogeneity in findings between studies was tested using I 2 test statistics. Sensitivity and specificity estimates with 95% confidence intervals (CI) were calculated on per patient basis and summary sensitivity on per polyp basis, using bivariate and univariate statistical models.ResultsThirty-seven studies were found to be potentially relevant and 13 fulfilled the inclusion criteria. The study population comprised 1,285 patients with a mean disease prevalence of 44% (range 22–63%). Sensitivity for the detection of CRC was 100%. Significant heterogeneity was found for overall per patient sensitivity and specificity. For polyps with a size of 10 mm or larger, per patient sensitivity and specificity estimates were 88% (95% CI 63–97%; I 2 = 37%) and 99% (95% CI 95–100%; I 2 = 60%). On a per polyp basis, polyps of 10 mm or larger were detected with a sensitivity of 84% (95% CI 66–94%; I 2 = 51%). The data were too heterogeneous for polyps smaller than 6 mm and 6–9 mm.ConclusionMR-colonography can accurately detect colorectal polyps more than 10 mm in size

Family relationships in childhood and common psychiatric disorders in later life: systematic review of prospective studies

Most evidence for associations between childhood adversity and adult mental illness is retrospective. To evaluate prospective evidence of associations between poor parent-child relationships and common psychiatric disorders in later life. Systematic review of studies published between 1970 and 2008 including: (a) more than 100 participants; (b) measures of relationships in the home during childhood; (c) at least 10 years between assessment of exposures; and (d) measures of anxiety, depression, suicide, suicidal ideation or post-traumatic stress disorder (PTSD). Analysis was by narrative synthesis. Twenty-three papers were identified reporting data from 16 cohorts. Abusive relationships predicted depression, anxiety and PTSD. Maternal emotional unavailability in early life predicted suicide attempts in adolescence. Results of studies investigating less severe relationship problems were suggestive but not conclusive of causal association, due partly to methodological heterogeneity. Given the prevalence and disabling nature of common psychiatric problems, these studies highlight the need to minimise harm associated with dysfunctional parent-child relationships.

C‐reactive protein and colorectal cancer risk: A systematic review of prospective studies

C-reactive protein is a sensitive but nonspecific systemic marker of inflammation. Several prospective studies have investigated the association of prediagnostic circulating C-reactive protein concentrations with the development of colorectal cancer, but the results have been inconsistent. We performed a systematic review of prospective studies of the association between prediagnostic measurements of circulating high-sensitivity C-reactive protein and development of invasive colorectal cancer. Authors of original studies were contacted to acquire uniform data. We combined relative risks (RR) for colorectal cancer associated with a one unit change in natural logarithm-transformed high-sensitivity C-reactive protein using inverse variance weighted random effects models. We identified eight eligible studies, which included 1,159 colorectal cancer cases and 37,986 controls. The summary RR per one unit change in natural log-transformed high-sensitivity C-reactive protein was 1.12 (95% confidence intervals [CI], 1.01-1.25) for colorectal cancer, 1.13 (95% CI, 1.00-1.27) for colon cancer, and 1.06 (95% CI, 0.86-1.30) for rectal cancer. The association was stronger in men (RR, 1.18; 95% CI, 1.04-1.34) compared to women (RR, 1.09; 95% CI, 0.93-1.27) but this difference was sensitive to the findings from a single study. Prediagnostic high-sensitivity C-reactive protein concentrations were weakly associated with an increased risk for colorectal cancer. More work is needed to understand the extent to which circulating high-sensitivity C-reactive protein or other blood inflammatory markers are related to colonic inflammation.

Cholesterol as a Risk Factor for Dementia and Cognitive Decline: A Systematic Review of Prospective Studies With Meta-Analysis

The relationships between total serum cholesterol (TC) and dementia and between TC and cognitive decline were investigated in a systematic review of 18 prospective studies. Follow-ups ranged from 3 to 29 years, and included a total of 14,331 participants evaluated for Alzheimer disease (AD), 9,458 participants evaluated for Vascular dementia (VaD), 1,893 participants evaluated for cognitive decline, and 4,793 participants evaluated for cognitive impairment. Compatible results were pooled using meta-analysis. Consistent associations between high midlife TC and increased risk of AD, and high midlife TC and increased risk of any dementia were found. There was no evidence supporting an association between late-life TC and AD, or between late-life TC and any dementia. No study reported a significant association between TC (measured in midlife or late-life) and VaD. An association between high midlife TC and cognitive impairment was found but there was only weak evidence for an association between TC and cognitive decline. Two of seven studies reporting data on the interaction between TC and apolipoprotein e4-allele had significant effects. Results suggest the effect of TC on dementia risk occurs in midlife but not late-life, and that there may be different cardiovascular risk factor profiles for AD and VaD. Results from additional studies involving long-term follow-up of midlife samples will allow for clarification of the association between age, TC and risk of specific types of dementia. These data are required to inform recommendations of modulation of cholesterol to reduce or delay dementia risk.

Effectiveness and Safety of EUS Guided Pancreatic Pseudocyst/Abscess Drainage: A Systematic Review of Prospective Studies

Effectiveness and Safety of EUS Guided Pancreatic Pseudocyst/Abscess Drainage: A Systematic Review of Prospective Studies

The risk of recurrent venous thromboembolism among heterozygous carriers of factor V Leiden or prothrombin G20210A mutation. A systematic review of prospective studies

Factor V Leiden (FVL) and prothrombin G20210A mutation (PTM) are the two most common genetic polymorphisms known to predispose to a first episode of venous thromboembolism (VTE). However, whether these thrombophilic abnormalities are also risk factors for recurrent VTE is unclear. We conducted a systematic review of prospective studies to assess the risk of recurrent VTE associated with heterozygous carriage of each of these mutations. All randomized controlled trials and prospective cohort studies that reported the incidence of recurrent VTE in patients with and without FVL and PTM after discontinuation of anticoagulant treatment were collected and analyzed. The risk ratios (RR) and their 95% confidence intervals (CI) for recurrent VTE were calculated in heterozygous carriers of FVL or PTM and compared to those of non-carriers. Eleven studies fulfilled the inclusion criteria. Recurrent VTE occurred in 114 out of 557 heterozygous carriers of FVL (20.5%) as compared to 382 out of 2,646 non-carriers (14.4%); and in 38 out of 212 heterozygous carriers of PTM (17.9%) compared to 428 of 2,996 non-carriers (14.3%). The RR of VTE recurrence conferred by the heterozygous carriage of FVL and PTM was 1.39 (95% CI, range 1.15 to 1.67) and 1.20 (range 0.89 to 1.61), respectively, using the Mantel-Haenszel fixed-effects model; 1.45 (1.13 to 1.85) and 1.36 (1.02 to 1.82), respectively, using the Der Simonian and Laird random effects method. In symptomatic patients with VTE, heterozygous carriage of FVL is clearly associated with a definitely increased risk of recurrent thromboembolism. The risk is lower with PTM and is difficult to interpret since it varies according to the assessment method used.

Skin Care in the Well Term Newborn: Two Systematic Reviews

Awareness is increasing that the use of some commercial products on the premature neonatal skin may be beneficial, whereas the use of others may be harmful. The World Health Organization developed general postnatal care guidelines and the Association of Women's Health, Obstetric and Neonatal Nurses published specific evidence-based guidance relating to neonatal skin care. No systematic reviews on the topic have focused on the term newborn. The objective of this review was to determine, for the well term baby, if the use of soaps or detergents in bath water is associated with the development of dry, cracked, or flaking skin in the perinatal period, and short- and long-term consequences of the use of emollients, lotions, or moisturizers for dry skin. We conducted a structured systematic review of prospective studies involving term newborns. No relevant studies were located. No prospective studies of research in skin care involving the term newborn were found. Some recommendations for skin care may balance risk and benefit for the compromised infant, but this balance may be different for the healthy term newborn. Clinical practitioners should be aware that outcomes related to the use of soaps, detergents, emollients, and lotions on the term neonatal skin have not been formally investigated. Systematic reviews that yield no formal results provide insights into unresearched areas of practice, and should be reported to highlight these deficits, and to avoid duplication of effort by future investigators.

Bilateral vs. ipsilateral venography as the primary efficacy outcome measure in thromboprophylaxis clinical trials: a systematic review

Contrast venography, in combination with symptomatic venous thromboembolism (VTE), is the standard efficacy outcome measure in clinical trials of thromboprophylaxis in major orthopedic surgery. It is uncertain whether performing bilateral venography offers any real advantage over venography of the operated leg alone. This study was undertaken to determine the risk of isolated contralateral deep vein thrombosis (DVT) following major orthopedic surgery and to evaluate whether bilateral venography, rather than venography on the operated leg alone, offers any gain in DVT detection and, thereby, improves efficiency in clinical study design. A systematic review of prospective studies that reported DVT incidence as the primary efficacy outcome based on mandatory bilateral venography in patients undergoing elective hip or knee arthroplasty or hip fracture repair was conducted. Based on the use of bilateral venography as a primary efficacy outcome measure, the incidence of any DVT is 16.7% following total hip replacement, 18.8% after hip fracture repair, and 33.8% after total knee replacement. While DVT risk in the operated leg varies depending on the type of surgery, the risk of isolated DVT in the non-operated leg is approximately 4% to 5% in all three procedures. By increasing the detection of any DVT, the use of bilateral venography reduces required sample size by 16% to 25% compared to ipsilateral venography. In clinical trials evaluating the efficacy of thromboprophylaxis in major orthopedic surgery, bilateral venography reduces the risk of undiagnosed DVT in the non-operated leg and improves the efficiency of study design by substantially reducing the sample size requirement.

Psychological interventions in bipolar disorder: From wishful thinking to an evidence-based approach.

We aimed to examine the historical and current relevance of psychosocial approaches to bipolar illness by conducting a systematic review of prospective studies assessing the effectiveness of psychological interventions for bipolar disorder. A systematic literature search was conducted using EMBASE, MedLine and PsychLIT and reference sections of papers were scrutinized for further relevant reports. Only four trials met the criteria of a prospective study and achieved the necessary methodological standards. The studies showed benefits for patients in terms of relapse prevention and the reduction of hospitalization rates. Psychoeducation (delivered in groups or as part of a family intervention) and cognitive behavioural therapy were also found to be effective prophylactic treatments for bipolar disorder in medicated patients. Other interventions do not appear to be supported by sufficient evidence. Psychological approaches, and particularly psychoeducation and cognitive-behavioural therapies, are evidence-based prophylactic therapies for bipolar patients receiving pharmacotherapy. They should be used as adjuncts to medication where possible in the prevention of bipolar disorder.

Subthreshold depression as a risk indicator for major depressive disorder: a systematic review of prospective studies.

In order to examine whether the incidence of major depressive disorder (MDD) is increased in subjects with subthreshold depression, or sD (clinically relevant depressive symptoms, without meeting criteria for a full-blown MDD), we conducted a review of prospective studies examining the incidence of MDD in subjects with sD. A systematic literature search was conducted. For all studies, the relative risk of developing MDD was calculated, based on person-years. Twenty studies (23 comparisons) were found, based on community samples, general medical patients and high-risk subjects. Most comparisons showed that subjects with sD had a consistently larger chance of developing MDD. The studies differed considerably in the definition of sD, the recency (occurrence of the last sD) and the in-/exclusion of lifetime MDD. The incidence of MDD in subjects with sD is larger than in subjects without sD. Otherwise, the concept of sD is too broad to be used. In future studies, some consensus should be reached regarding the definition of sD.