External validation of a smartphone app model to predict the need for massive transfusion using five different definitions.

BACKGROUND: Previously, a model to predict massive transfusion protocol (MTP) (activation) was derived using a single-institution data set. The PRospective, Observational, Multicenter, Major Trauma Transfusion database was used to externally validate this model's ability to predict both MTP activation and massive transfusion (MT) administration using multiple MT definitions. METHODS: The app model was used to calculate the predicted probability of MTP activation or MT delivery. The five definitions of MT used were: (1) 10 units packed red blood cells (PRBCs) in 24 hours, (2) Resuscitation Intensity score ≥ 4, (3) critical administration threshold, (4) 4 units PRBCs in 4 hours; and (5) 6 units PRBCs in 6 hours. Receiver operating curves were plotted to compare the predicted probability of MT with observed outcomes. RESULTS: Of 1,245 patients in the data set, 297 (24%) met definition 1, 570 (47%) met definition 2, 364 (33%) met definition 3, 599 met definition 4 (49.1%), and 395 met definition 5 (32.4%). Regardless of the outcome (MTP activation or MT administration), the predictive ability of the app model was consistent: when predicting activation of the MTP, the area under the curve for the model was 0.694 and when predicting MT administration, the area under the curve ranged from 0.695 to 0.711. CONCLUSION: Regardless of the definition of MT used, the app model demonstrates moderate ability to predict the need for MT in an external, homogenous population. Importantly, the app allows the model to be iteratively recalibrated ("machine learning") and thus could improve its predictive capability as additional data are accrued. LEVEL OF EVIDENCE: Diagnostic test study/Prognostic study, level III.

Hand problems in migrant farmworkers.

PURPOSE: We estimated the self-reported prevalence of hand problems and identified factors associated with them in this cross-sectional study including 390 farmworkers representing 180 migrant farmworker families from Starr County, Texas. METHODS: A two-year cohort study (1999-2001), "Injury and Illness Surveillance in Migrant Farmworkers (MANOS), "provided the data for this study. We calculated the prevalence for the two-year follow-up period, stratified by family member and survey year. The associated work and non-work factors were identified for the entire sample using multilevel mixed-effects logistic regression analysis. RESULTS: Prevalence for hand problems was 29.0% and 17.8% for the first and second study years, respectively. Significant factors (associated odds ratios) included increasing age (1.07), female gender (3.49), duration of sleep while migrating (0.68), participation group working in both study years 1 and 2 (0.21) or year 2 only (0.14), working on average more than 11 hours per day (8.23), moving heavy objects at work (3.97), working with hand-held vibrating tools/machinery (5.16), and working in meat processing (40.48). CONCLUSIONS: The prevalence of hand problems in migrant farmworkers reported by this study was notable for mothers, fathers, and children. Further research with refined ergonomic exposure and outcome assessments for investigating hand injuries in migrant farmworkers is indicated, specifically among youth. The role of sleep in preventing symptoms should also be explored.

Pesticide safety training among farmworker adolescents from Starr County, Texas.

This study of adolescent farmworkers describes employer compliance with pesticide safety training, a requirement of the EPA-mandated Worker Protection Standard (WPS), and identifies variables associated with having received training within the prior five years. Data are from "A Study of Work Injuries in Farmworker Children, " a three-year cohort study of high school students living along the Texas-Mexico border in Starr County. Data were collected using a web-based, self-administered, confidential survey. Of 324 students who participated in field work between January 1 and September 30, 2003, 68 (21.0%) reported ever receiving pesticide safety training. Overall, the 61 (18.8%) students who reported training within the prior five years also reported that their most recent instruction covered at least three key WPS areas (i.e., entry into a recently treated field, pesticide-related injuries/illnesses, and emergency care for pesticide exposure). Based on a multiple logistic regression, students who were male (OR = 1.97), worked only outside of Texas (OR = 2.73), worked only for commercial growers/owners (OR = 4.35), worked only for contractors (OR = 3.18), worked corn crops (OR = 2.93), and worked potato crops (OR = 3.11) were more likely to report receipt of training within the prior five years. Results suggest that increased enforcement may be needed, especially in Texas, and special educational efforts may be needed to reach female farmworker youth.

Rett syndrome: an analysis using Sartwell's incubation period model.

Evidence suggests that Rett syndrome is a genetic disorder; however, an etiologic genetic model has yet to be identified. The purpose of this study was to apply a statistical model, Sartwell's incubation period model, to estimate the incubation period of Rett syndrome and postulate further on the etiology of Rett syndrome. Sartwell's model was used to test the hypothesis that the age of onset of developmental regression distributions approximate a logarithmic normal model and thus the etiologic factors of Rett syndrome occur in utero or prior to conception. Data from three case-series of Rett syndrome from different geographic regions were used for the analyses. Curves resulting from the analyses demonstrated a good approximation to the logarithmic normal distribution, indicating a good fit of the data to Sartwell's model. In conclusion, the incubation period of Rett syndrome fits the logarithmic normal model, which is consistent with the theory that a major causal factor for Rett syndrome most likely occurs in utero or prior to conception, eg, a defective gene.

The association between the quality of inpatient care and early readmission: a meta-analysis of the evidence.

OBJECTIVES: To help resolve the current controversy over the validity of early readmission as an indicator of the quality of care, the authors critically reviewed the literature using meta-analysis to derive summary estimates of effect and evaluate inter-study heterogeneity. METHODS: The authors selected reports meeting five criteria: (1) presentation of new data on medical-surgical hospitalization of adults; (2) measurement of outcome as a person-specific readmission; (3) readmission within < or = 31 days; (4) examination of some aspect of the process of inpatient care; (5) inclusion of a comparison group. One meta-analysis examined 13 comparisons of readmission rates after substandard versus normative care, another examined 9 comparisons of readmission rates after normative versus exceptional care, and the third examined all 22 comparisons together. Two authors applied inclusion criteria and extracted data on methods and findings. Two others classified studies on 11 methodological variables for the heterogeneity evaluation. RESULTS: The summary odds ratio for readmission after substandard care was 1.24 (0.99-1.57) relative to normative care; for readmission after normative care the summary odds ratio was 1.45 (0.90-2.33) relative to exceptional care. The individual odds ratios varied significantly (chi2, 21 df = 50.34, P = 0.0003). Most of the variance in study odds ratios could be explained by whether the study focused on the quality of patient care or the qualifications of patient care providers. The summary odds ratio for the 16 homogeneous comparisons focusing on the quality of patient care was 1.55 (1.25-1.92). CONCLUSIONS: Early readmission is significantly associated with the process of inpatient care. The risk of early readmission is increased by 55% when care is of relatively low quality, that is, substandard or normative instead of normative or exceptional.

Comparison of 2-year weight loss trends in behavioral treatments of obesity: diet, exercise, and combination interventions.

OBJECTIVE: The effects of three cognitive-behavioral weight control interventions for adults were compared: diet only, exercise only, and a combination of diet and exercise. This article reports 2-year follow-up data. DESIGN: The three interventions were compared in a randomized, experimental design. SUBJECTS: A total of 127 men and women who were at least 14 kg overweight (according to height-weight tables) were recruited from an urban community and assigned randomly to the experimental conditions. INTERVENTION: The dietary intervention was a low-energy eating plan adjusted to produce a 1 kg/week loss of weight. The exercise component involved training in walking and a home-based program of up to five exercise periods per week. There were 12 weekly instructional sessions, followed by 3 biweekly and 8 monthly meetings. All sessions were led by registered dietitians. OUTCOME MEASURES: Changes in body weight. STATISTICAL ANALYSES: Analysis of variance for weight changes and repeated measures analysis of variance for weight change trends. RESULTS: At 1 year, no significant differences were noted among the three groups. The diet-only group lost 6.8 kg, the exercise-only group lost 2.9 kg, and the combination group lost 8.9 kg (P=.09). During the second year, the diet-only group regained weight--reaching 0.9 kg above baseline; the combination group regained to 2.2 kg below baseline; and the exercise-only group regained slightly to 2.7 kg below baseline (P=.36). Repeated measures analysis of variance showed a group-by-time interaction (P=.001); data for the dieting groups best fit a U-shaped regain curve (P=.001). APPLICATIONS: The results suggest that dieting is associated with weight loss followed by regain after treatment ends, whereas exercise alone produced smaller weight losses but better maintenance. The large outcome variability and unequal difficulty of the regimens across groups limit the generalizability of the findings.

Population-based registries using multidisciplinary reporters: a method for the study of pediatric neurologic disorders.

Few registries are available for evaluating population differences for rare, newly, or ill-defined pediatric neurologic disorders. The purpose of this article is to present standard methodologies for establishing a population-based registry and evaluating the completeness of a registry's case ascertainment. The Texas Rett Syndrome Registry (TRSR) is used as a model. The combination of health care and education resources has identified approx. 89-100% of the Rett syndrome cases in Texas. Cases reported by non-physician sources, although older on average (10.7 vs 7.7 years of age), did not differ by other demographic characteristics from those reported by physicians. Non-physician health and education professionals participated with the TRSR at a significantly higher rate than physicians, 89 and 37% (p < 0.05), respectively. Capture-recapture techniques, both two-sample and log-linear modeling, were used to quantitatively evaluate case ascertainment. Standardized national and international population-based registries could be the basis of an initiative to identify the etiology and perhaps preventive measures for pediatric neurologic disorders.

The pattern of growth failure in Rett syndrome.

OBJECTIVE: To define the growth pattern of girls with Rett syndrome with respect to height, weight, and fronto-occipital head circumference. DESIGN: Longitudinal with irregular intervals between measurements. SETTING: Rett Syndrome Program Project at Baylor College of Medicine, Houston, Tex. PARTICIPANTS: Ninety-six girls fulfilling criteria for Rett syndrome; comparison group with standard growth curves. SELECTION PROCEDURE: Consecutive entries into the Rett Syndrome Program Project. INTERVENTION: None. MEASUREMENTS/MAIN RESULTS: Height, weight, and fronto-occipital head circumference data were grouped into intervals. Group medians were then generated. Regression lines were fitted through the median points and plotted on standard growth charts. Deceleration of growth velocities began at age 3 months and persisted through age 18 years. CONCLUSIONS: Early deceleration of head growth, followed by deceleration of weight and height measurements, appears to be a growth pattern characteristic of Rett syndrome. This pattern of growth may provide the earliest clinical indicator for the diagnosis of Rett syndrome.

Do oral contraceptives prevent rheumatoid arthritis?

Two studies have suggested that the risk of rheumatoid arthritis in women using oral contraceptives is less than half that of nonusers. When a third study from the Mayo Clinic failed to confirm these findings, it was criticized for inclusion of ineligible subjects, misclassification of oral contraceptive use, and inadequate statistical power. Recent expansion of the Mayo Clinic's data resources provided a unique opportunity to resolve the controversy, and a new population-based case-control study was undertaken. In comparison with the previous study, the new investigation had 2.2 times as many eligible cases and more complete ascertainment of oral contraceptive use via access to the records of Planned Parenthood of Minnesota. Comparing any prior use of oral contraceptives with never having used them, the relative risk of rheumatoid arthritis estimated from 182 cases and their 182 matched controls was 1.1 (95% confidence interval 0.7 to 1.7). The relative risk for current use was 1.3 (95% confidence interval, 0.7 to 2.4). The lack of a protective effect was independent of age, disease severity, and disease end point (date of confirmed diagnosis or symptom onset).

Comparison of direct wet mount and trichrome staining techniques for detecting Entamoeba species trophozoites in stools.

Simulated freshly passed stools containing motile Entamoeba moshkovskii trophozoites were examined by direct wet mount and permanent (Trichrome) staining techniques. The percentage of detection by direct mount was 4.8%. The percentage of detection of the trophozoites by direct mount plus permanent stain was 58.5%. Laboratorians should be cautioned not to rely solely on the direct wet mount for detection or identification of protozoan trophozoites.