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Assessment of clinical enzyme methodology: a probabilistic approach.

A number of techniques are available to assess the clinical value of enzyme methodologies including regression and discriminant analyses, expert systems, neural networks, and probabilistic. Each has its adherents but the probabilistic approach appears to be the most commonly used technique. This approach uses the fourfold contingency table that categorises subjects by both the presence or absence of the target disease-as defined by a gold standard test- and by a test result being above or below a chosen decision threshold. From this classification can be defined the test's sensitivity and specificity. By altering the decision threshold across the entire range of test values a series of sensitivity:specificity pairs can be tabulated. These may be plotted as 1-specificity (or false positive rate or fraction) versus sensitivity (or true positive rate or fraction) to create a receiver operator characteristic (ROC) curve. ROC curves can provide the accuracy of the test (the area under the curve with associated confidence intervals), the rule-in and rule-out decision thresholds, and the clinical power of the test (likelihood ratio). However, a review of three years' publications in a peer-reviewed journal indicated that much of this essential data is usually absent. It is argued that such publications should include the decision thresholds used, the area under the curve and its standard error, a statistical assessment of the difference between two or more ROC plots, the rule-in and rule-out decision thresholds (indicating if these change with time after the onset of disease), and the relevant likelihood ratios.

Clinical Enzyme Tests↗

Contemporary outcome trends in the elderly undergoing percutaneous coronary interventions: results in 7,472 octogenarians. National Cardiovascular Network Collaboration.

OBJECTIVES: We sought to define the risks facing octogenarians undergoing contemporary percutaneous coronary interventions (PCIs). BACKGROUND: The procedural risks of PCI for octogenarians have not been well established. METHODS: We compared the clinical characteristics and in-hospital outcomes of 7,472 octogenarians (mean age 83 years) with those of 102,236 younger patients (mean age 62 years) who underwent PCI at 22 National Cardiovascular Network (NCN) hospitals from 1994 through 1997. RESULTS: Octogenarians had more comorbidities, more extensive coronary disease and a two- to fourfold increased risk of complications, including death (3.8% vs. 1.1%), Qwave myocardial infarction (1.9% vs. 1.3%), stroke (0.58% vs. 0.23%), renal failure (3.2% vs. 1.0%) and vascular complications (6.7% vs. 3.3%) (p < 0.001 for all comparisons). Independent predictors of procedural mortality in octogenarians included shock (odds ratio [OR] 5.4, 95% confidence interval [CI] 3.3 to 8.8), acute myocardial infarction (OR 3.2, 95% CI 2.3 to 4.4), left ventricular ejection fraction (LVEF) <35% (OR 2.9, 95% CI 2.1 to 3.9), renal insufficiency (OR 2.8, 95% CI 2.0 to 3.8), first PCI (OR 2.3, 95% CI 1.7 to 3.3), age >85 years (OR 2.1, 95% CI 1.5 to 2.7) and diabetes mellitus (OR 1.5, 95% CI 1.1 to 2.0). For elective procedures, octogenarian mortality varied nearly 10-fold, and was strongly influenced by comorbidities (0.79% mortality with no risk factors vs. 7.2% with renal insufficiency or LVEF <35%). Despite similar case-mix, PCI outcomes in octogenarians improved significantly over the four years of observation (OR of 0.61 for death/myocardial infarction/stroke in 1997 vs. 1994; 95% CI 0.45 to 0.85). CONCLUSIONS: Risks to octogenarians undergoing PCI are two- to fourfold higher than those of younger patients, strongly influenced by comorbidities, and have decreased in the stent era.

Aged↗

Sustained ventricular arrhythmias among patients with acute coronary syndromes with no ST-segment elevation: incidence, predictors, and outcomes.

BACKGROUND: The prognosis of ventricular arrhythmias among patients with non-ST-elevation acute coronary syndromes is unknown. We studied the incidence, predictors, and outcomes of sustained ventricular arrhythmias in 4 large randomized trials of such patients. METHODS AND RESULTS: We pooled the datasets of the Global Use of Streptokinase and tPA for Occluded Arteries (GUSTO)-IIb, Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT), Platelet IIb/IIIa Antagonism for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network (PARAGON)-A, and PARAGON-B trials (n=26 416). We identified independent predictors of ventricular fibrillation (VF) and ventricular tachycardia (VT) and compared the 30-day and 6-month mortality rates of patients who did (n=552) and did not (n=25 864) develop these arrhythmias during the index hospitalization. Independent predictors of in-hospital VF included prior hypertension, chronic obstructive pulmonary disease, prior myocardial infarction, and ST-segment changes at presentation. Except for hypertension, these variables also independently predicted in-hospital VT. In Cox proportional-hazards modeling, in-hospital VF and VT were independently associated with 30-day mortality (hazard ratio [HR], 23.2 [95% CI, 18.1 to 29.8] for VF and HR, 7.6 [95% CI, 5.5 to 10.4] for VT) and 6-month mortality (HR, 14.8 [95% CI, 12.1 to 18.3] for VF and HR, 5.0 [95% CI, 3.8 to 6.5] for VT). These differences remained significant after excluding patients with heart failure or cardiogenic shock and those who died <24 hours after enrollment. CONCLUSIONS: Despite the use of effective therapies for non-ST-elevation acute coronary syndromes, ventricular arrhythmias in this setting are associated with increased 30-day and 6-month mortality. More effective therapies are needed to improve the survival of patients with these arrhythmias.

Acute Disease↗

The preterm prediction study: quantitative fetal fibronectin values and the prediction of spontaneous preterm birth. The National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVE: A cervicovaginal fetal fibronectin value of >/=50 ng/mL has been used to define women at risk of having a preterm birth. We evaluated the relationship between quantitative fetal fibronectin values and spontaneous preterm birth. STUDY DESIGN: Cervical and vaginal specimens for fetal fibronectin were obtained at 24, 26, 28, and 30 weeks' gestation from 2926 women. Quantitative fetal fibronectin values were calculated by using absorbances determined by enzyme-linked immunosorbent assay. The highest fetal fibronectin value (cervical or vaginal) for each woman at each visit was evaluated in relation to spontaneous preterm birth at <35 weeks' gestation. Receiver operating characteristic curves were constructed to determine the optimal cutoff point for fetal fibronectin values to predict spontaneous preterm birth at <35 weeks' gestation and within 4 weeks of testing. RESULTS: The risk of spontaneous preterm birth increased as a function of increasing fetal fibronectin values from approximately 20 to 300 ng/mL. Fetal fibronectin values > or =300 ng/mL were not associated with a further increase in spontaneous preterm birth. Examination of the receiver operating characteristic curve indicates that the optimal cutoff point for a positive fetal fibronectin test result at 24 to 30 weeks' gestation to predict spontaneous preterm birth at <35 weeks is between 45 and 60 ng/mL. CONCLUSION: Increasing levels of cervicovaginal fetal fibronectin up to 300 ng/mL are associated with an increasing risk of spontaneous preterm birth. Nevertheless, at 24 to 30 weeks, the value currently used, 50 ng of fetal fibronectin per milliliter, appears to be a reasonable cutoff point for predicting spontaneous preterm birth at <35 weeks' gestation.

Cervix Uteri↗

Gender differences in illhealth in Finland: patterns, magnitude and change.

The common wisdom about gender differences in illhealth has been encapsulated in the phrase "women are sicker, but men die quicker". Recently this wisdom has been increasingly questioned. The purpose of this study is first to analyse the patterns and magnitude of gender differences across various indicators of illhealth; second to examine changes over time in these differences and third to assess whether sociodemographic and socioeconomic, family status and social network determinants have any bearing on the differences. The data derive from nationally representative 1986 and 1994 Surveys on Living Conditions in Finland. Women showed poorer health for five out of eight indicators analysed; that is somatic symptoms, mental symptoms, disability among those 50 years or older, long-standing illness and limiting long-standing illness were more prevalent among women than men. Male excess was found for perceived health below good and extremely limiting long-standing illness among those 50 years or older. However, the male excess was statistically significant only for poor perceived health among those 50 years or older. Adjusting for a number of suggested determinants of health had a negligible effect on gender differences. Further analyses showed that gender differences in illhealth remained largely stable over the eight year study period which saw a steep increase of unemployment for both genders. Only in the case of mental and somatic symptoms have gender differences declined, with a simultaneous increase in the prevalence of such symptoms. Otherwise gender differences in illhealth turned out to be resistant to the deep labour market crisis over this relatively short period of time. Although women had poorer health than men for a number of health indicators, we also find gender equality and even male excess for some indicators. Furthermore, the results suggest that a male excess in illhealth is likely to be found with more severe domains of illhealth among elderly people.

Adult↗

Caring for demented people in their homes or in sheltered accommodation as reflected on by home-care staff during clinical supervision sessions.

This study aimed to illuminate both the content of and the care given to demented people and the reflections of home care staff about it as revealed in two clinical group supervision sessions (n = 36). Verbatim transcriptions were analysed using a phenomenological hermeneutic approach and the following were found to be reflected on: the pensioners' personal situation--disease-related behaviour, ADL-functions, social network and self-esteem; the pensioners' environment--their relationships to significant others, adequate level of housing/care, access to activities, and satisfactory personal space; pensioner/staff interaction--their relations to each other, the staffs' relation to the pensioners' family, and the balance between reality-orientation vs. validation; the staff's situation--co-operation with other professionals, in primary health care, hospital, and within the social services; job satisfaction, lack of knowledge and sharing of knowledge, and lack of resources, especially time. The reasoning of the participants under supervision was found to be based on medical, historical, psychological, and environmental explanations, or personal beliefs. Feelings explored during supervision were directed towards the pensioners or the pensioners' families, towards themselves or towards the management. The findings were interpreted within a nursing model based on the four central concepts of nursing; person, environment, nursing intervention and health. The reasoning about nursing care revealed in the supervision sessions reflected a holistic approach and the relationship between the staff and the demented person stood out as central for care quality. Thus focusing on what promotes or, respectively, obstructs this relationship is likely to be one important focus in clinical supervision not only to achieve improvement and high quality in home care but also to develop and enhance the quality of the working life of the staff. Since the results could be understood within a theoretical nursing care model, it may well be that if the supervisor functions within some theoretical model the participants may reach a more conscious approach and the risk of losing important aspects of caring will decrease.

Adaptation, Psychological↗

Genome-wide association study meta-analysis provides insights into the etiology of heart failure and its subtypes.

Heart failure (HF) is a major contributor to global morbidity and mortality. While distinct clinical subtypes, defined by etiology and left ventricular ejection fraction, are well recognized, their genetic determinants remain inadequately understood. In this study, we report a genome-wide association study of HF and its subtypes in a sample of 1.9 million individuals. A total of 153,174 individuals had HF, of whom 44,012 had a nonischemic etiology (ni-HF). A subset of patients with ni-HF were stratified based on left ventricular systolic function, where data were available, identifying 5,406 individuals with reduced ejection fraction and 3,841 with preserved ejection fraction. We identify 66 genetic loci associated with HF and its subtypes, 37 of which have not previously been reported. Using functionally informed gene prioritization methods, we predict effector genes for each identified locus, and map these to etiologic disease clusters through phenome-wide association analysis, network analysis and colocalization. Through heritability enrichment analysis, we highlight the role of extracardiac tissues in disease etiology. We then examine the differential associations of upstream risk factors with HF subtypes using Mendelian randomization. These findings extend our understanding of the mechanisms underlying HF etiology and may inform future approaches to prevention and treatment.

Humans↗

Association between the alpha-adducin gene and hypertension in the HyperGEN Study.

This report from the HyperGEN Study, one of four networks participating in the NHLBI-sponsored Family Blood Pressure Program, presents the results of an association study based on 822 white and 572 black subjects (cases and controls) participating in the HyperGEN Network from five geographically diverse field centers. All cases met the Joint National Committee on Detection and Treatment of High Blood Pressure (JNC VI) criteria for hypertension (Stage I or higher). Each subject was clinically examined for risk factors for hypertension as well as genotyped for the point mutation Gly460Trp at the alpha-adducin locus on chromosome 4p. In the white group, the prevalence of genotypes with one or more Trp alleles was 26% in normotensives, versus 33% in hypertensives randomly selected from the population, and 39% among the multiply affected hypertensive sibships. Overall, in whites, the Trp allele significantly increased the odds of hypertension (P = .0056), with an odds ratio (OR) of 1.73 (95% confidence interval [CI] = 1.17, 2.54). The alpha-adducin gene remained a significant independent predictor of hypertension in a multivariate logistic model even after correcting for other risk factors for hypertension, including gender, age, body mass index (BMI), smoking, LDL cholesterol, triglycerides, urine sodium (Na), and urine potassium (K), (OR = 1.55, 95% CI = 1.03, 2.34). Through the use of regression trees, several gene-by-environment interactions were implicated, suggesting that alpha-adducin appears to be a particularly important risk factor (OR = 4.2) for older (age > 60.5 years), less lean (BMI < 25.8 kg/m2) subjects with moderately high triglycerides (between 145.5 and 218.5 mg/dL). In the black group, the relationship was less clear. Overall, it was protective against hypertension. The prevalence of genotypes with one or more Trp alleles was 24% among normotensive versus 11% in hypertensive black subjects randomly selected from the population, and 13% among multiply affected hypertensive sibships, resulting in an OR of 0.48 (P = .0231; 95% CI = 0.25, 0.90). However, the Trp genotype was no longer a significant independent predictor of hypertension risk in the multivariate logistic model (OR = 0.79; 95% CI = 0.37, 1.67), suggesting that it may be operating through one or more of these other factors. Thus, we conclude that the alpha-adducin gene is a significant, independent risk factor for hypertension in whites, but not in blacks, and may play a particularly important role for subjects with certain constellations of other risk factors.

Alleles↗

Helmets for preventing head and facial injuries in bicyclists.

BACKGROUND: Each year, in the United states, approximately 900 persons die from injuries due to bicycle crashes and over 500,000 persons are treated in emergency departments. Head injury is by far the greatest risk posed to bicyclists, comprising one-third of emergency department visits, two-thirds of hospital admissions, and three-fourths of deaths. Facial injuries to cyclists occur at a rate nearly identical to that of head injuries. Although it makes inherent sense that helmets would be protective against head injury, establishing the real-world effectiveness of helmets is important. A number of case-control studies have been conducted demonstrating the effectiveness of bicycle helmets. Because of the magnitude of the problem and the potential effectiveness of bicycle helmets, the objective of this review is to determine whether bicycle helmets reduce head, brain and facial injury for bicyclists of all ages involved in a bicycle crash or fall. OBJECTIVES: To determine whether bicycle helmets reduce head, brain and facial injury for bicyclists of all ages involved in a bicycle crash or fall. SEARCH STRATEGY: We searched The Cochrane Controlled Trials Register, MEDLINE, EMBASE, Sport, ERIC, NTIS, Expanded Academic Index, CINAHL, PsycINFO, Occupational Safety and Health, and Dissertations Abstracts. We checked reference lists of past reviews and review articles, studies from government agencies in the United States, Europe and Australia, and contacted colleagues from the International Society for Child and Adolescent Injury Prevention, World Injury Network, CDC funded Injury Control and Research Centers, and staff in injury research agencies around the world. SELECTION CRITERIA: Controlled studies that evaluated the effect of helmet use in a population of bicyclists who had experienced a crash. We required that studies have complete outcome ascertainment, accurate exposure measurement, appropriate selection of the comparison group and elimination or control of factors such as selection bias, observation bias and confounding. DATA COLLECTION AND ANALYSIS: Five published studies met the selection criteria. Two abstractors using a standard abstraction form independently abstracted data. Odds ratios with 95% CI were calculated for the protective effect of helmet for head and facial injuries. Study results are presented individually. Head and brain injury results were also summarized using meta-analysis techniques. MAIN RESULTS: No randomized controlled trials were found. This review identified five well conducted case control studies which met our selection criteria. Helmets provide a 63%-88% reduction in the risk of head, brain and severe brain injury for all ages of bicyclists. Helmets provide equal levels of protection for crashes involving motor vehicles (69%) and crashes from all other causes (68%). Injuries to the upper and mid facial areas are reduced 65%. REVIEWER'S CONCLUSIONS: Helmets reduce bicycle-related head and facial injuries for bicyclists of all ages involved in all types of crashes including those involving motor vehicles.

Bicycling↗

Strategies to improve recruitment to randomised trials.

BACKGROUND: Recruiting participants to randomised controlled trials (RCTs) is challenging. Identifying effective recruitment strategies would benefit health research: poor recruitment leads to underpowered trials, reducing the reliability of findings and increasing the risk of wasted resources, ethical concerns, and trial failure. Evidence to inform recruitment strategies is increasingly generated through Studies Within A Trial (SWATs), which are methodological studies embedded within host RCTs. This is an update of a review last published in 2018. OBJECTIVES: Primary: to quantify the effects of strategies to improve recruitment of participants to RCTs. Secondary: to evaluate recruitment strategies' cost-effectiveness and impact on retention, and the equity, diversity, and inclusion (EDI) characteristics of recruited participants. SEARCH METHODS: We used MEDLINE, Embase, and six other databases to identify the studies included in the review. We also sought unpublished recruitment SWATs through social media and targeted email dissemination to trial methodology networks. The latest search date was 16 February 2023. SELECTION CRITERIA: We included randomised SWATs evaluating trial recruitment strategies embedded in healthcare and non-healthcare trials. We excluded quasi-randomised, hypothetical, questionnaire-only, retention-only, or clinician incentive studies. DATA COLLECTION AND ANALYSIS: Primary outcome: proportion of eligible participants or centres recruited. SECONDARY OUTCOMES: cost-effectiveness, retention rates, and EDI characteristics of included participants. We conducted random-effects meta-analysis for strategies evaluated in at least two studies; otherwise, we synthesised results narratively. We reported effects as risk differences (RDs) with 95% confidence intervals (CIs), and assessed between-trial heterogeneity. We used GRADE to assess the certainty of evidence for the primary outcome. We expressed cost-effectiveness as the incremental cost per additional participant recruited in pounds sterling (GBP). MAIN RESULTS: We identified 91 eligible studies (53 new to this update), providing 94 comparisons and involving at least 176,747 participants. Eighty-one studies involved strategies aimed at trial participants, while 10 evaluated strategies aimed at recruiters. All were healthcare studies. We found 65 recruitment strategies; 49 were evaluated in a single study. Only five strategies were supported by high-certainty evidence according to GRADE criteria, and we focus on these strategies in the summary below. Open-label trials versus blinded, placebo trials. Open-label trials recruited more participants than blinded trials (RD 10%, 95% CI 8% to 12%; 3 studies, 9004 participants), corresponding to approximately 10 additional participants per 100 approached. The studies involved mostly women in the UK and Estonia. No cost or retention data were reported. Telephone reminder versus no telephone reminder. Telephone reminders to people who did not respond to an initial postal invitation boosted recruitment by 6% (95% CI 3% to 9%; 2 studies, 1450 participants), in trials with low underlying recruitment (we are less certain for trials with over 10% recruitment). The studies involved people with a mean age of 58 years in Canada and Norway. No cost or retention data were reported. Recruitment primer letter versus no letter. Pre-recruitment letters and leaflets designed to encourage participation made little or no difference to recruitment (absolute improvement 1%, 95% CI -1% to 2%; 2 studies, 5376 participants), and were associated with increased costs compared to not sending a primer (incremental cost: GBP 2.08). The studies involved mostly older white people in the UK and Ireland. Multimedia information via a digital link/QR code plus paper participant information leaflet (PIL) versus paper PIL alone. This made little or no difference to recruitment (absolute improvement 0%, 95% CI -1% to 1%; 7 studies, 11,612 participants) and retention (absolute improvement 0%, 95% CI -2% to 3%; 5 studies, 7403 participants), and increased costs compared to not including multimedia information (incremental cost: GBP 0.78). The studies involved people in the UK. Optimised, user-tested PIL versus standard PIL. Optimising participant information leaflets (e.g. through user-testing the leaflet with the target population to shape its content, format, and appearance) made little or no difference to recruitment: absolute improvement was 0% (95% CI 0% to 1%; 6 studies, 27,805 participants). The studies involved people in the UK. Only one study reported EDI data; participants were mostly older women. No cost or retention data were reported. We had moderate-certainty evidence for 13 other strategies; confidence was often reduced because the results came from single studies. Seven strategies involved changes to how potential participants received information; four involved changes to trial conduct; one targeted the recruiter or recruitment site; and one tested non-monetary incentives. We had much less confidence in the other 47 comparisons because the studies had design flaws, were single studies, or had very uncertain results. Costs were reported in only 17 of 91 studies. Strategy impact on retention was reported in 15 studies. All but one study (99%) were from high-income countries. The most reported demographics were age (49 studies), sex (32 studies), gender (27 studies), and education level (16 studies). AUTHORS' CONCLUSIONS: The evidence on strategies to improve trial recruitment remains broad but lacks depth. Of 65 strategies evaluated, only five were supported by high-certainty evidence. Open-label trial designs and telephone reminders to non-responders increased recruitment, while optimised participant information leaflets, recruitment primer letters, and multimedia information provided alongside a paper participant information leaflet had little or no effect. Reporting of participant characteristics was poor, limiting assessment of equity, diversity, and inclusion across most studies. Evidence is heavily skewed toward high-income countries. Future research must prioritise evaluations in low-to-middle-income settings and consistently report cost, retention, and EDI outcomes. We strongly urge the methodology research community to strengthen the evidence base by prioritising replications of existing strategies over the development and testing of new ones. FUNDING: National Institute for Health and Care Research (Advanced Fellowship, Adwoa Parker, reference:NIHR302256). Health Research Board, Republic of Ireland, Evidence Synthesis Ireland (grant ESI-2021-001) REGISTRATION: This review updates an earlier Cochrane review, which was first published in 2002 and subsequently updated in 2007, 2010, and 2018. Previous versions of the review and their protocols are available at: https://doi.org/10.1002/14651858.MR000013.pub2 https://doi.org/10.1002/14651858.MR000013.pub3 https://doi.org/10.1002/14651858.MR000013.pub4 https://doi.org/10.1002/14651858.MR000013.pub5 https://doi.org/10.1002/14651858.MR000013.pub6.

Randomized Controlled Trials as Topic↗

Changes in the legislation on the use of daytime running lights by motor vehicles and their effect on road safety in Hungary.

As of 1 March 1993, a partial (relating only to semi-motorways and main roads), and as of 1 June 1994, a total (relating to all roads) legal obligation to use DRL came into force outside built-up areas in Hungary. This paper examines the effectiveness of this regulation as an accident countermeasure. In view of the fact that it became possible to use one part of the road network as a comparison group during the period of partial obligation, a comparison group investigation has been carried out in addition to the analysis based on the odds ratio method familiar from earlier studies. The different methods provided different results, the probable causes of which are discussed in the present study. The result of the comparison group analysis are consistent not only with the hypothesis that DRL reduces certain types of collisions, but also with the results of a meta-analysis of 17 studies that have evaluated the effects on accidents of using DRL on cars. By using this method, it was possible to detect in the experimental group a 13.0% reduction in the number of frontal and 'crossing' vehicle collisions in daylight, in good visibility conditions, during the after period. The number of frontal and crossing collisions decreased without a simultaneous increase in rear-end collisions: the number of the latter has not significantly changed. Thus, the hypothesis that it is more reliable to estimate the collision-reducing effect of DRL on the basis of accidents only occurring in good visibility conditions, rather than on the basis of the total number of daylight accidents, has been justified by this study. The causes of this, as well as the difficulties and confounding factors arising when the odds ratio method is used, are dealt with in this work. By analyzing over a longer time series, it was possible to verify that the positive road safety effect is not a mere novelty effect, and is not simply due to the 'regression to the mean'.

Accident Prevention↗

Antibiotics and return visits for respiratory illness: a comparison of pooled versus hierarchical statistical methods.

BACKGROUND: Antibiotic prescribing for respiratory illness has been associated with small reductions in return visits in an analysis of a large practice-based network. In this study, we apply hierarchical analytical methods that account for the clustering of patients by practices to identify whether antibiotic prescribing by primary care physicians reduces subsequent visits for 6 acute respiratory illnesses-upper respiratory infection, pharyngitis, bronchitis, otitis media, sinusitis, and cough. METHODS: The study data came from 318 family physicians and internists in 45 practices in the Practice Partner Research Network from January 1995 through December 1996, with 255,564 active patients. Patients treated with antibiotics were compared with those who were not on the frequency of revisit within the next 14 days. A simple pooling model and 3 hierarchical statistical models (fixed-effects, random-effects, and Bayesian) were used to compare the odds-ratios for return visits. RESULTS: Statistically significant results were found only for bronchitis and sinusitis by the hierarchical models, but the simple pooling model produced statistically significant results for all study conditions. CONCLUSION: We conclude that antibiotics may reduce return visits for patients with bronchitis and sinusitis, but not for patients with other respiratory illness (upper respiratory infection, pharyngitis, otitis media, or cough). Studies of large clinical databases should use methods of analysis that account for the grouping of patients by practice to avoid false positive associations (type I errors.)

Academic Medical Centers↗

Studies of Pediatric Liver Transplantation (SPLIT): year 2000 outcomes.

BACKGROUND: Initiated in 1995, the Studies of Pediatric Liver Transplantation (SPLIT) registry database is a cooperative research network of pediatric transplantation centers in the United States and Canada. The primary objectives are to characterize and follow trends in transplant indications, transplantation techniques, and outcomes (e.g., patient/graft survival, rejection, growth parameters, and immunosuppressive therapy.) METHODS: As of June 15, 2000, 29 centers registered 1144 patients, 640 of whom received their first liver-only transplant while registered in SPLIT. Patients are followed every 6 months for 2 years and yearly thereafter. Data are submitted to a central coordinating center. RESULTS: One/two-year patient survival and graft loss estimates are 0.85/0.82 and 0.77/0.72, respectively. Risk factors for death include: in ICU at transplant (relative risk (RR)=2.63, P<0.05) and height/weight deficits of two or more standard deviations (RR=1.67, P<0.05). Risk factors for graft loss include: in ICU at transplant (RR=1.77, P<0.05) and receiving a cadaveric split organ compared with a whole organ (RR=2.3, P<0.05). The percentage of patients diagnosed with hepatic a. and portal v. thrombosis were 9.7% and 7%, respectively; 15% had biliary complications within 30 days. At least one re-operation was required in 45%. One/two-year rejection probability estimates are 0.60/0.66. Tacrolimus, as primary therapy posttransplant, reduces first rejection risk (RR=0.70, P<0.05). Eighty-nine percent of school-aged children are in school full-time, 18 months posttransplant. CONCLUSIONS: This report provides one of the first descriptions of characteristics and clinical courses of a multicenter pediatric transplant population. Observations are subject to patient selection biases but are useful for generating hypothesis for future studies.

Adolescent↗

Dialysis, kidney transplantation, or pancreas transplantation for patients with diabetes mellitus and renal failure: a decision analysis of treatment options.

Patients with type 1 diabetes mellitus and end-stage renal disease may remain on dialysis or undergo cadaveric kidney transplantation, living kidney transplantation, sequential pancreas after living kidney transplantation, or simultaneous pancreas-kidney transplantation. It is unclear which of these options is most effective. The objective of this study was to determine the optimal treatment strategy for type 1 diabetic patients with renal failure using a decision analytic Markov model. Input data were obtained from the published medical literature, the United Network for Organ Sharing registry, and patient interviews. The outcome measures were life expectancy (in life-years [LY]) and quality-adjusted life expectancy (in quality-adjusted life-years [QALY]). Living kidney transplantation was associated with 18.30 LY and 10.29 QALY; pancreas after kidney transplantation, 17.21 LY and 10.00 QALY; simultaneous pancreas-kidney transplantation, 15.74 LY and 9.09 QALY; cadaveric kidney transplantation, 11.44 LY and 6.53 QALY; dialysis, 7.82 LY and 4.52 QALY. The results were sensitive to the value of several key variables. Simultaneous pancreas-kidney transplantation had the greatest life expectancy and quality-adjusted life expectancy when living kidney transplantation was excluded from the analysis. These data indicate that living kidney transplantation is associated with the greatest life expectancy and quality-adjusted life expectancy for type 1 diabetic patients with renal failure. Treatment strategies involving pancreas transplantation should be considered for patients with frequent metabolic complications of diabetes and for those patients who favor kidney-pancreas transplantation over kidney transplantation alone. For patients without a living donor, simultaneous pancreas-kidney transplantation is associated with the greatest life expectancy.

Adult↗

Health risk assessment of inorganic arsenic: an umbrella review.

Inorganic arsenic (iAs) is a toxic environmental pollutant linked to serious health risks, prompting global regulatory efforts. This study identifies major health conditions associated with iAs exposure using text network analysis, and assesses health risk assessments through an umbrella review and dose-response analysis. It synthesizes previous systematic reviews to offer a broader perspective on iAs-related health effects. An optimized text network analysis-based search strategy was applied across multiple databases to identify relevant systematic reviews. An umbrella review framework was employed to synthesize and reinterpret findings across systematic reviews. The methodological quality of included systematic reviews was assessed using the A MeaSurement Tool to Assess systematic Reviews 2 tool. Extracted data on study characteristics, exposure levels, and risk estimates were analyzed to evaluate the dose-response relationship between iAs exposure and health outcomes. From 922 systematic reviews, 36 were included and categorized into 10 health condition groups. For example, seven SRs found a significant dose-response relationship between iAs and bladder cancer, with one systematic review reporting relative risks of 2.70, 4.20, and 5.80 at 10, 50, and 150&#x202f;&#xb5;g/L, respectively. Individual study analysis further showed that each 10&#x202f;&#xb5;g/L increase in iAs raised bladder cancer risk by 3.11&#x202f;% (p=0.003). iAs exposure is associated with hypertension, diabetes, cardiovascular disease, and adverse fetal outcomes. Dose-dependent increases in bladder cancer, lung cancer, and hypertension risks were observed. These findings support more precise health risk assessments and regulatory strategies.

Humans↗

The impact of stressful life events and social support on drinking among older adults: a general population survey.

This article is an analysis of stressful life events, the buffering hypothesis, and alcohol use in a national sample of 1,418 respondents 60 years of age and over. The results indicate that older adults who experience stressful losses are significantly more likely to drink excessively than those who have not experienced such losses or who have experienced them to a lesser extent. Increased drinking among older adults may therefore be a reaction to life circumstances in which alcohol represents an attempt to cope with traumatic loss, personal as well as within the kinship network. Supportive resources of spouse, family, friends, and church appear to have a stress-buffering effects that reduces the excessive-drinking response to life crisis. Data suggest, however, that older persons are vulnerable to the magnitude of losses experienced as they grow older and lose more of their family, friends, and peers. These stressors appear to seriously impact their drinking behavior and are not effectively buffered. Respondents report that drinking may increase during periods of prolonged exposure to emotionally depleting life change and loss, when supportive needs may exceed the capacities of personal and social support resources.

Adaptation, Psychological↗

Multifactorial analysis of renal transplants reported to the United Network for Organ Sharing Registry: a 1994 update.

1. From a multivariate log-linear analysis of 57,303 renal transplants between 1988 and 1994, the top 10 factors influencing one-year and 3-year cadaveric graft survival rates were ranked as follows: [table: see text] 2. Center effects accounted for 30% and 28% of all assignable variations in one-year and 3-year outcomes, respectively. Although center variation dominated 32 other variables, most factors were relatively independent of transplant center. 3. Novel to our own multifactorial analyses of the UNOS Kidney Transplant Registry were 6 pretransplant factors (recipient pretransplant dialysis, pregnancy, PRA technique, donor disposition and preservation, and ABO compatibility). Survival rates over the various combinations of these new factors were not significantly different. 4. For the first time in our multivariate analyses, 4 posttransplantation factors (delayed graft function, rejection episodes prior to discharge, induction and maintenance drug therapies) were included in the log-linear model. It is noteworthy that graft survival in both transplant periods was seriously imperiled following delayed graft function or rejection prior to discharge, yet the accounting for these pseudo-outcome variables did not alter the influence of the remaining 31 transplant factors. Finally, maintenance drug therapies strongly influenced short-term outcomes but did not influence long-term results, except for a noteworthy trend toward increased survival rates for FK506 therapy.

Adolescent↗

Managed care plan performance since 1980. A literature analysis.

OBJECTIVE: To compare the health care utilization, expenditure, quality of care, and satisfaction since 1980 of enrollees in managed care and indemnity plans. DATA SOURCES AND STUDY SELECTION: Studies selected met the following criteria: data from 1980 forward, private insurance or Medicare enrollees, a comparison group, a reasonable attempt at statistical adjustment for noncomparable managed care and indemnity plan enrollees, and peer-reviewed findings (with two exceptions). Few studies on preferred provider organization plan performance met the selection criteria. DATA SYNTHESIS: Compared with indemnity plans, health maintenance organization plans had somewhat lower hospital admission rates, 1% to 20% shorter hospital length of stay, the same or more physician office visits per enrollee, less use of expensive procedures and tests, greater use of preventive services, mixed results on outcomes, and somewhat lower enrollee satisfaction with services but higher satisfaction with costs. The evidence does not support the hypothesis that prepaid group practice or staff model health maintenance organizations are more effective than individual practice association or network model health maintenance organizations. CONCLUSIONS: Although this literature analysis found several clear patterns of results, several factors, including unmeasured selection bias, diverse and rapidly changing health plans and local market conditions, and relatively few research results, suggest that generalizations must be made with caution.

Health Care Costs↗