Biomedical subjects

Stephen D Walter

Publications and source records attributed to Stephen D Walter.

36 records · Page 2Linked to original sources

PubMed2004

Caregiving process and caregiver burden: conceptual models to guide research and practice.

BACKGROUND: Parental care for a child with a developmental disability is an enormous responsibility, one that can far exceed that of typical parental care. While most parents adapt well to the situation of caring for a child with a disability, some do not. To understand parents' adaptations to their children's disabilities, the complex nature of stress processes must be accounted for and the constructs and factors that play a role in the caregiving must be considered. DISCUSSION: Evidence suggests that there is considerable variation in how caregivers adapt to their caregiving demands. Many studies have sought to qualify the association between caregiving and health outcomes of the caregivers. Contextual factors such as SES, child factors such as child behaviour problems and severity of disability, intra-psychic factors such as mastery and self-esteem, coping strategies and social supports have all been associated with psychological and/or physical outcome or parents or primary caregivers. In reviewing these issues, the literature appears to be limited by the use of traditional analytic approaches which examine the relationship between a factor and an outcome. It is clear, however, that changes to single factors, as represented in these studies, occur very rarely even in the experimental context. The literature has also been limited by lack of reliance on specific theoretical frameworks. SUMMARY: This conceptual paper documents the state of current knowledge and explores the current theoretical frameworks that have been used to describe the caregiving process from two diverse fields, pediatrics and geriatrics. Integration of these models into one comprehensive model suitable for this population of children with disabilities and their caregivers is proposed. This model may guide future research in this area.

Adaptation, Psychological↗

PubMed2004

DNR directives are established early in mechanically ventilated intensive care unit patients.

PURPOSE: Setting treatment goals in the intensive care unit (ICU) often involves resuscitation decisions. Our objective was to study the rate of establishing do-not-resuscitate (DNR) directives, determinants, and outcomes of those directives for mechanically ventilated patients. METHODS: In a multicentre observational study, we included consecutive adults with no DNR directives within 24 hr of ICU admission who were mechanically ventilated for at least 48 hr. We identified the rate with which DNR directives were established, and factors associated with these directives. RESULTS: Among 765 patients, DNR directives were established for 231 (30.2%) patients; 143 (62.1%) of these were established within the first week. Factors independently associated with a DNR directive were: patient age [> or = 75 yr (hazard ratio [HR] 2.3, 95% confidence interval 1.5-3.4], 65 to 74 yr (HR 1.8, 1.2-2.7), 50 to 64 yr (HR 1.4, 1.0-2.2) relative to < 50 yr); medical rather than surgical diagnosis (HR 1.8, 1.3-2.5); multiple organ dysfunction score (HR 1.7 for each five-point increment, 1.4-2.0); physician prediction of ICU survival [< 10% (HR 15.0, 6.7-33.6)], 10 to 40% [(HR 5.0, 2.3-11.2), 41 to 60% (HR 4.0, 1.8-9.0) relative to > 90%]; and physician perception of patient preference to limit life support (no advanced life support [(HR 5.8, 3.6-9.4) or partial advanced life support (HR 3.2, 2.2-4.6) compared to full measures]. CONCLUSION: One third of mechanically ventilated patients had DNR directives established early during their ICU stay after the first 24 hr of admission. The strongest predictors of DNR directives were physician prediction of low probability of survival, physician perception of patient preference to limit life support, organ dysfunction, medical diagnosis and age.

APACHE↗

PubMed2004

Adjustment for baseline measurement error in randomized controlled trials induces bias.

When estimating the treatment effect in a randomized controlled trial, it is common to have a continuous outcome which is also observed at baseline. These observations are often prone to measurement error, for example due to within-patient variability. Controversy exists in the literature about whether baseline measurement error should be adjusted for in this context. Computer simulations were used to compare the biases in the estimated treatment effect, with and without adjusting for measurement error, and for different levels of observed baseline imbalance. The impacts of sample size (30 per group and 300 per group) and reliability coefficient (0.6, 0.8 and 1) were also assessed. The results show that in randomized controlled trials, the ordinary least squares (OLS) estimator without adjusting for measurement error is unbiased. On the contrary, adjusting for measurement error leads to bias, especially when sample sizes are small and/or measurement error is large. The treatment effect adjusting for measurement error is on average overestimated when the baseline mean of the control group is larger than that of the treated group. It is underestimated when the control group has a smaller baseline mean.

Analysis of Variance↗

PubMed2004

The number needed to treat (NNT) can be adjusted for bias when the outcome is measured with error.

BACKGROUND AND OBJECTIVE: We consider the number needed to treat (NNT) when the event of interest is defined by dichotomizing a continuous response at a threshold level. If the response is measured with error, the resulting NNT is biased. We consider methods to reduce this bias. METHODS: Bias adjustment was studied using simulations in which we varied the distributions of the underlying response and measurement error, including both normal and nonnormal distributions. We studied a maximum likelihood estimate (MLE) based on normality assumptions, and also considered a simulation-extrapolation estimate (SIMEX) without such assumptions. The treatment effect across all potential thresholds was summarized using an NNT threshold curve. RESULTS: Crude NNT estimation was substantially biased due to measurement error. The MLE performed well under normality, and it continued to perform well with nonnormal measurement error, but when the underlying response was nonnormal the MLE was unacceptably biased and was outperformed by the SIMEX estimate. The simulation results were also reflected in empirical data from a randomized study of cholesterol-lowering therapy. CONCLUSION: Ignoring measurement error can lead to substantial bias in NNT, which can have an important practical effect on the interpretation of analyses. Analysis methods that adjust for measurement error bias can be used to assess the sensitivity of NNT estimates to this effect.

Bias↗

PubMed2004

Limb distribution, motor impairment, and functional classification of cerebral palsy.

This study explored the relationships between the Gross Motor Function Classification System (GMFCS), limb distribution, and type of motor impairment. Data used were collected in the Ontario Motor Growth study, a longitudinal cohort study with a population-based sample of children with cerebral palsy (CP) in Canada (n=657; age 1 to 13 years at study onset). The majority (87.8%) of children with hemiplegia were classified as level I. Children with a bilateral syndrome were represented in all GMFCS levels, with most in levels III, IV, and V. Classifications by GMFCS and 'limb distribution' or by GMFCS and 'type of motor impairment' were statistically significantly associated (Pearson's chi2 p<0.001), though the correlation for limb distribution (two categories) by GMFCS was low (tau-b=0.43). An analysis of function (GMFCS) by impairment (limb distribution) indicates that the latter clinical characteristic does not add prognostic value over GMFCS. Although classification of CP by impairment level is useful for clinical and epidemiological purposes, the value of these subgroups as an indicator of mobility is limited in comparison with the classification of severity with the GMFCS.

Adolescent↗

PubMed2004

Facility-level correlates of antimicrobial use in nursing homes.

We assessed the contribution of facility-level variables to antimicrobial use in a cohort of 50 nursing homes and found that antimicrobial use was significantly correlated with the percentage of nursing home residents with feeding tubes, the number of healthcare aides, and the country of origin of the facility.

Anti-Infective Agents↗

PubMed2004

The health of primary caregivers of children with cerebral palsy: how does it compare with that of other Canadian caregivers?

BACKGROUND: Caring for any child involves considerable resources, but the demands for these resources are often increased when caring for a child with a disability. These demands have implications for the psychologic and physical health of the caregiver (CG). Although a number of recent trends in health care stress the importance of studying and promoting the health of CGs of children with disabilities, the literature in this area exhibits 2 major weaknesses, ie, most studies draw conclusions from relatively small, potentially biased, clinic-based samples and the majority of work has focused on the psychologic health of CGs, whereas little research has been undertaken to study their physical well-being. The goal of this study was to compare the physical and psychologic health of CGs of children with cerebral palsy (CP) with that of the general population of CGs. METHODS: Data on the physical and psychologic health of 468 primary CGs of children with CP, drawn from 18 of 19 publicly funded children's rehabilitation centers in Ontario, Canada, were collected with a self-completed questionnaire and a face-to-face interview. Identical items and scales had been administered previously to nationally representative samples of the Canadian population in 2 large-scale Canadian surveys, ie, the National Population Health Survey (NPHS) and the National Longitudinal Study of Children and Youth (NLSCY). Subsamples of those data, restricted to adult residents of the province of Ontario who were parents, allowed a comparison of our sample of CGs of children with CP with parent samples from both the NLSCY (n = 2414) and the NPHS (n = 5549). OUTCOME MEASURES: Demographic variables included CG age, gender, education, income, and work-related variables. Psychologic health and support variables included social support, family functioning, frequency of contacts, distress, and emotional and cognitive problems. Physical health variables included the number and variety of chronic conditions, vision, hearing, and mobility problems, and experience of pain. RESULTS: CGs of children with CP had lower incomes than did the general population of CGs (proportion with income over 60,000 dollars: CG: 40.9%; NLSCY: 51.4%), despite the absence of any important differences in education between the 2 samples. Results showed that CGs of children with CP were less likely to report working for pay (CG: 66%; NLSCY: 81.2%), less likely to be engaged in full-time work (CG: 67.5%; NLSCY: 73.2%), and more likely to list caring for their families as their main activity (CG: 37.2%; NLSCY: 28.4%). Measures of support showed no difference in reported social support (CG: mean score: 14.5; SD: 3.4; NLSCY: mean score: 14.3; SD: 2.7) or family functioning (CG: mean score: 8.6; SD: 5.6; NLSCY: mean score: 9.0; SD: 4.9) between the 2 samples, although the CG sample did report a statistically greater number of support contacts (CG: mean score: 4.5; SD: 0.7; NPHS: mean score: 4.2; SD: 0.9). Measures of psychologic health showed greater reported distress (CG: mean score: 4.7; SD: 4.4; NPHS: mean score: 2.2; SD: 2.7), chronicity of distress (CG: mean score: 5.5; SD: 1.4; NPHS: mean score: 5.2; SD: 1.1), emotional problems (CG: 25.3% indicating problems; NPHS: 13.7%), and cognitive problems (CG: 38.8%; NPHS: 14.3%) among CGs of children with CP. They also reported a greater likelihood of a variety of physical problems, including back problems (CG: 35.5% reporting the condition; SE: 2.2%; NLSCY: 12.2%; SE: 0.7%), migraine headaches (CG: 24.2%; SE: 2.0%; NLSCY: 11.2%; SE: 0.7%), stomach/intestinal ulcers (CG: 8.4%; SE: 1.3%; NLSCY: 1.7%; SE: 0.3%), asthma (CG: 15.8%; SE: 1.7%; NLSCY: 6.3%; SE: 0.5%), arthritis/rheumatism (CG: 17.3%; SE: 1.8%; NLSCY: 7.3%; SE: 0.5%), and experience of pain (CG: 28.8%; SE: 2.1%; NPHS: 11.0%; SE: 0.5), as well as a greater overall number of chronic physical conditions (CG: 24.1% reporting no chronic conditions; NLSCY: 55.2%). CONCLUSIONS: Although many families cope well despite the added challenges of caring for a child with a disability, our findings suggest that the demands of their children's disabilities can explain differences in the health status of parents and that parents of children with CP are more likely to have a variety of physical and psychologic health problems. Many of these findings are consistent with a stress process model, in which stress from caregiving can directly or indirectly affect a variety of measures of health, although some of the findings (asthma and arthritis) seem to strain this hypothesis. Alternate interpretations of these findings include the possibility that parents who are in regular contact with the health care system may have more opportunities to discuss and receive attention for their own health concerns than do comparison adults or that the greater number of health issues reported by CGs is related to the nature of our study, perhaps leading these parents to focus on their health and well-being in more depth than is usually feasible in a population survey. CGs of children with CP also had lower incomes, despite the absence of any important differences in education. The findings are consistent with the idea that the financial burden of caring for a child with a disability results in part from a reduced availability of these parents to work for pay. IMPLICATIONS FOR SERVICE PROVIDERS: Physicians and other health care professionals should be aware of the important relationship between child disability and CG health. Family-centered policies and services that explicitly consider CG health are likely to benefit the well-being of both CGs and their families. Future work should address the extent to which the family-centeredness of services, as experienced by CGs, is associated with better health outcomes for parents and their families.

Adult↗

PubMed2004

SARS among critical care nurses, Toronto.

To determine factors that predispose or protect healthcare workers from severe acute respiratory syndrome (SARS), we conducted a retrospective cohort study among 43 nurses who worked in two Toronto critical care units with SARS patients. Eight of 32 nurses who entered a SARS patient's room were infected. The probability of SARS infection was 6% per shift worked. Assisting during intubation, suctioning before intubation, and manipulating the oxygen mask were high-risk activities. Consistently wearing a mask (either surgical or particulate respirator type N95) while caring for a SARS patient was protective for the nurses, and consistent use of the N95 mask was more protective than not wearing a mask. Risk was reduced by consistent use of a surgical mask, but not significantly. Risk was lower with consistent use of a N95 mask than with consistent use of a surgical mask. We conclude that activities related to intubation increase SARS risk and use of a mask (particularly a N95 mask) is protective.

Cohort Studies↗

PubMed2004

Nursing home residents and Enterobacteriaceae resistant to third-generation cephalosporins.

Limited data identify the risk factors for infection with Enterobacteriaceae resistant to third-generation cephalosporins among residents of long-term-care facilities. Using a nested case-control study design, nursing home residents with clinical isolates of Enterobacteriaceae resistant to third-generation cephalosporins were compared to residents with isolates of Enterobacteriaceae susceptible to third-generation cephalosporins. Data were collected on antimicrobial drug exposure 10 weeks before detection of the isolates, facility-level demographics, hygiene facilities, and staffing levels. Logistic regression models were built to adjust for confounding variables. Twenty-seven case-residents were identified and compared to 85 controls. Exposure to any cephalosporin (adjusted odds ratio [OR] 4.0, 95% confidence interval [CI] 1.2 to 13.6) and log percentage of residents using gastrostomy tubes within the nursing home (adjusted OR 3.9, 95% CI 1.3 to 12.0) were associated with having a clinical isolate resistant to third-generation cephalosporins.

Aged↗

PubMed2003

Risk factors for resistance to antimicrobial agents among nursing home residents.

The authors prospectively collected data on exposure to antimicrobial agents and susceptibility patterns among all clinical isolates of bacteria taken from 9,156 residents of 50 nursing homes in Canada and the United States in 1998-1999. Exposure to antimicrobial agents was measured during the 10 weeks prior to detection of targeted resistant bacteria in residents and compared with antibiotic exposure during a 10-week interval in individuals with sensitive organisms. These main effects were adjusted for infection-control and staffing covariates using multiple logistic regression modeling. Increased staffing of nursing homes with registered nurses (adjusted odds ratio (OR) = 0.79 (95% confidence interval (CI): 0.72, 0.87) per registered nurse per 100 resident-days) and use of antibacterial soap (adjusted OR = 0.40, 95% CI: 0.18, 0.90) were associated with reduced risk of methicillin-resistant Staphylococcus aureus in nursing home residents. An increase in the number of hand-washing sinks per 100 residents was shown to reduce the risk of trimethoprim-sulfamethoxazole (TMP/SMX)-resistant Enterobacteriaceae (adjusted OR = 0.94, 95% CI: 0.90, 0.98). Exposure to TMP-SMX and exposure to fluoroquinolones were significant risk factors for isolation of TMP-SMX-resistant Enterobacteriaciae (adjusted OR = 1.14, 95% CI: 1.06, 1.22) and fluoroquinolone-resistant Enterobacteriaciae (adjusted OR = 1.08, 95% CI: 1.04, 1.11), respectively. These findings suggest that increased staffing, more hand-washing sinks, and use of antimicrobial soap may reduce resistance to antimicrobial agents in long-term care facilities.

Anti-Bacterial Agents↗

PubMed2003

Rasch analysis of the Gross Motor Function Measure: validating the assumptions of the Rasch model to create an interval-level measure.

OBJECTIVES: To describe the Rasch analysis of the Gross Motor Function Measure (GMFM-88) and to demonstrate how the assumptions of unidimensionality, sample-free measurement, and test-free measurement were validated to create an interval level measure. DESIGN: Cross-sectional and longitudinal (12-mo) data from a prospective study of motor development in children with cerebral palsy (CP) were used for the analysis. SETTING: Motor assessments were completed at 18 children's ambulatory rehabilitation centers in Ontario, Canada, by pediatric physical therapists trained in the use of the GMFM-88. PARTICIPANTS: The first 537 of 682 children enrolled into a longitudinal study of motor development in children with CP. Children had a mean age of 6.43+/-2.75 years (range, 11mo-12y) with varying types and severity of CP. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The GMFM-88. RESULTS: The Rasch analysis, in conjunction with clinical decisions, identified 66 items from the GMFM-88 that formed a unidimensional measure (GMFM-66). Assumptions of sample-free and test-free measurement were confirmed, and a user-friendly scoring program was developed. CONCLUSIONS: The GMFM-66 is an interval-level measure of gross motor function for children with CP; it should improve the scoring, interpretation, and overall clinical and research utility over the original GMFM.

Algorithms↗

PubMed2003

Adjunctive human papillomavirus testing in the 2-year follow-up of women with low-grade cervical cytologic abnormalities: a randomized trial and economic evaluation.

CONTEXT: Although human papillomavirus (HPV) testing may aid in managing low-grade abnormality on screening cervical cytology, patient compliance with repeat testing programs requires consideration. OBJECTIVES: To determine effectiveness and costs of repeated Papanicolaou (Pap) test and oncogenic HPV testing for detecting cervical intraepithelial neoplasia 2 or 3. DESIGN: We conducted a randomized controlled trial of combined Pap test and cervical HPV testing by Hybrid Capture 1 test compared with Pap test alone; tests were performed every 6 months for up to 2 years. The study end point was colposcopic examination performed on all women at 2 years, or earlier if an HPV test was positive or if a Pap test showed high-grade squamous intraepithelial lesion. SETTING: Sixty-six community family practices. PARTICIPANTS: Two hundred fifty-seven women with atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion on screening cervical cytology. MAIN OUTCOME MEASURES: Detection of histologically confirmed cervical intraepithelial neoplasia 2 or 3, fully allocated costs, and loss to follow-up. RESULTS: Combined Pap test and HPV testing detected 11 (100%) of 11 cases of cervical intraepithelial neoplasia 2/3, whereas Pap test alone detected 7 (63.6%) of these 11 cases (P =.14); corresponding specificities were 39 (46.4%) of 84 and 45 (71.4%) of 63 (P =.005). The cost-effectiveness ratio was Can $4456 per additional case of high-grade cervical intraepithelial neoplasia. Sixty-nine (26.8%) of the 257 women (24.6% combined group vs 29.1% Pap test only group, P =.41) defaulted from testing or from colposcopy when referred with an abnormal result. CONCLUSIONS: Combined testing was more costly but may detect more cases of cervical intraepithelial neoplasia 2/3 than Pap test alone. However, poor adherence limits usefulness of a management strategy that requires repeated follow-up.

Adult↗

PubMed2003

Effect of environmental setting on mobility methods of children with cerebral palsy.

The aim of this study was to: (1) describe the usual mobility methods of children with cerebral palsy (CP) at home, school, and outdoors or in the community and (2) examine whether children with CP are more dependent on adult assistance for mobility in certain settings. The participants were a stratified random sample of 636 children with CP (355 males and 281 females; 2 to 12 years of age, mean 6.8 years SD 2.7), receiving rehabilitation services in Ontario, Canada. Children were grouped by age and Gross Motor Function Classification System (GMFCS) level. Among the five levels of the GMFCS, there were 185 children classified at level I, 81 children at level II, 113 children at level III, 132 children at level IV, and 125 children at level V. Information on children's usual mobility was obtained by parent report. The results of logistic regression indicated that compared with the school setting, children were more dependent on adult assistance for mobility when outdoors/in the community and less dependent at home. The majority of children aged from 4 to 12 years at levels III to V used wheelchair mobility at school and outdoors or in the community, however, only a small percentage self-propelled their wheelchair or used powered mobility. Of the children aged 4 to 12 years at level V, 39% were carried at home. The findings suggest that environmental setting is an important consideration for assessment and intervention to improve mobility of children with CP. For children who do not walk, attention should be given to the needs of caregivers and factors that are important for successful powered mobility.

Activities of Daily Living↗

PubMed2003

Development of hand function among children with cerebral palsy: growth curve analysis for ages 16 to 70 months.

This study documents the development of hand and upper-extremity function in young children who have cerebral palsy (CP) with upper-extremity involvement using longitudinal data. Assessments of hand function and the quality of upper-extremity movement were conducted on 29 males and 22 females (mean age 36.2 months, SD 10.6; age range 16 to 60 months at baseline) and on four other occasions over 10 months. Linear mixed effects modeling was used to estimate average developmental curves and the degree of individual differences in the patterns of development which were conditional on the body-site distribution of CP and severity of impairments. Results indicate that hand function in this clinical population develops differently from overall upper-extremity skills with declines in function in upper-extremity skills being more common and pronounced among older children. However, there is substantial interindividual variation. Distribution of CP and severity of impairments were significant predictors of development. Results are discussed in terms of their clinical implications.

Age Factors↗

PubMed2002

Prognosis for gross motor function in cerebral palsy: creation of motor development curves.

CONTEXT: Lack of a valid classification of severity of cerebral palsy and the absence of longitudinal data on which to base an opinion have made it difficult to consider prognostic issues accurately. OBJECTIVE: To describe patterns of gross motor development of children with cerebral palsy by severity, using longitudinal observations, as a basis for prognostic counseling with parents and for planning clinical management. DESIGN: Longitudinal cohort study of children with cerebral palsy, stratified by age and severity of motor function and observed serially for up to 4 years during the period from 1996 to 2001. SETTING: Nineteen publicly funded regional children's ambulatory rehabilitation programs in Ontario. PARTICIPANTS: A total of 657 children aged 1 to 13 years at study onset, representing the full spectrum of clinical severity of motor impairment in children with cerebral palsy. MAIN OUTCOME MEASURES: Severity of cerebral palsy, classified with the 5-level Gross Motor Function Classification System; function, formally assessed with the Gross Motor Function Measure (GMFM). RESULTS: Based on a total of 2632 GMFM assessments, 5 distinct motor development curves were created; these describe important and significant differences in the rates and limits of gross motor development among children with cerebral palsy by severity. There is substantial within-stratum variation in gross motor development. CONCLUSIONS: Evidence-based prognostication about gross motor progress in children with cerebral palsy is now possible, providing parents and clinicians with a means to plan interventions and to judge progress over time. Further work is needed to describe motor function of adolescents with cerebral palsy.

Adolescent↗

PubMed2002

Assessing the gain in diagnostic performance when combining two diagnostic tests.

Combining dichotomous (or dichotomized) results of two diagnostic tests will result in a trade-off in sensitivity and specificity of the combined test relative to the component tests. Because of this inherent trade-off, likelihood ratios provide a clinically relevant means of comparing the combined test with one of its components. The likelihood ratios depend on both sensitivity and specificity and hence take into account the trade-off between them. A graphical approach is used to assess whether the combined test is superior to a component test, or vice versa. Asymptotic standard errors are derived for comparing likelihood ratios when a paired study design is used. The trade-off in the expected number of additional true positive and false positive results (or true negative and false negative results) is used as the basis for deciding whether to use tests in combination when neither the combined nor a component test shows superior test performance based on their likelihood ratios. These methods are illustrated with an example that considers the combined use of Pap and HPV testing.

Diagnostic Tests, Routine↗

PubMed2002

A systematic review and meta-analysis of studies comparing mortality rates of private for-profit and private not-for-profit hospitals.

BACKGROUND: Canadians are engaged in an intense debate about the relative merits of private for-profit versus private not-for-profit health care delivery. To inform this debate, we undertook a systematic review and meta-analysis of studies comparing the mortality rates of private for-profit hospitals and those of private not-for-profit hospitals. METHODS: We identified studies through an electronic search of 11 bibliographical databases, our own files, consultation with experts, reference lists, PubMed and SciSearch. We masked the study results before determining study eligibility. Our eligibility criteria included observational studies or randomized controlled trials that compared private for-profit and private not-for-profit hospitals. We excluded studies that evaluated mortality rates in hospitals with a particular profit status that subsequently converted to the other profit status. For each study, we calculated a relative risk of mortality for private for-profit hospitals relative to private not-for-profit hospitals and pooled the studies of adult populations that included adjustment for potential confounders (e.g., teaching status, severity of illness) using a random effects model. RESULTS: Fifteen observational studies, involving more than 26 000 hospitals and 38 million patients, fulfilled the eligibility criteria. In the studies of adult populations, with adjustment for potential confounders, private for-profit hospitals were associated with an increased risk of death (relative risk [RR] 1.020, 95% confidence interval [CI] 1.003-1.038; p = 0.02). The one perinatal study with adjustment for potential confounders also showed an increased risk of death in private for-profit hospitals (RR 1.095, 95% CI 1.050-1.141; p < 0.0001). INTERPRETATION: Our meta-analysis suggests that private for-profit ownership of hospitals, in comparison with private not-for-profit ownership, results in a higher risk of death for patients.

Hospital Mortality↗

PubMed2002

The application of latent class analysis for diagnostic test validation of chronic Trypanosoma cruzi infection in blood donors.

The main strategy to prevent transfusion-associated Chagas disease is the identification of T. cruzi-infected blood donors by serological screening tests, however there is no perfect serological gold standard. We evaluated an enzyme immunoassay (EIA), an indirect hemaglutination (IHA), and an indirect immunofluorescence (IIF) test for detecting T. cruzi antibodies in Brazilian blood donors. The results were submitted to latent class analysis, and a radioimmunopreciptation (RIPA) test was performed on repeatedly positive samples. Among 1951 donors, 11 (0.56%) were positive by EIA, 6 (0.31%) by IHA and 16 (0.82%) by IIF. Six samples were positive with all tests, while 4 reacted with EIA and IIF. The RIPA was positive in 6 (75.0%), 7 (66.6%), and 4 (54.0%) samples reacting by the EIA, IHA and IIF tests, respectively. The latent class model detected a high sensitivity rate (100%) for the EIA and IIF, and a specificity rate of 99.95% and 99.69% for the EIA and IIF tests, respectively. The probability of being case according to the model was 99.92% when both EIA and IIF were positive, and 100% for the association of EIA, IIF, and IHA.

Adult↗