Biomedical subjects

R Platt

Publications and source records attributed to R Platt.

At least 55 records · Page 3Linked to original sources

PubMed2000

Fever in pediatric primary care: occurrence, management, and outcomes.

OBJECTIVE: To describe the epidemiology, management, and outcomes of children with fever in pediatric primary care practice. PATIENTS: A cohort of 20 585 children 3 to 36 months of age cared for in 11 pediatric offices of a health maintenance organization between 1991 and 1994. METHODS: Using automated medical records we identified all office visits with temperatures >/=38 degrees C for a random sample of 5000 children, and analyzed diagnoses conferred, laboratory tests performed, and antibiotics prescribed. We also determined the frequency of in-person and telephone follow-up after initial visits for fever. Finally, we reviewed hospital claims data for the entire cohort of 20 585 to identify cases of meningitis, meningococcal sepsis, and death from infection. RESULTS: Among 3819 initial visits of an illness episode, 41% of children had no diagnosed bacterial or specific viral source. Of these, 13% with a temperature of 38 degrees C to 39 degrees C and 36% with a temperature of >/=39 degrees C received laboratory testing. Almost half (43%) received some documented follow-up care in the subsequent 7 days. Among the 26 970 child-years of observation in the entire cohort, 15 children (56 per 100 000 child-years) were treated for bacterial meningitis or meningococcal sepsis. Five had an office visit for fever in the week before hospitalization, but only 1 had documented fever >/=39 degrees C and received neither laboratory testing for occult bacteremia nor treatment with an antibiotic. CONCLUSION: The majority of febrile children in ambulatory settings were diagnosed with a bacterial infection and treated with an antibiotic. Of highly febrile children without a source, 36% received laboratory testing consistent with published expert recommendations, and short-term follow-up was common. Meningitis or death after an office visit for fever without a source was predictably rare. These data suggest that increased testing and/or treatment of febrile children beyond the rates observed here are unlikely to affect population rates of meningitis substantially.

Ambulatory Care↗

PubMed2000

Ultrasound and a new videobronchoscopic technique to measure the subglottic diameter.

OBJECTIVE: The aim of this study was to evaluate ultrasound (US) and a new videobronchoscopic (VB) technique in the measurement of the subglottic lumen diameter. DESIGN: This blind prospective animal study of 62 recently sacrificed rabbits was conducted at the Montreal Children's Hospital. METHODS: Three different diameter measurements of the subglottis were assessed using B-mode US on each intact animal. The same diameter measurements, as well as a fourth, were estimated with a VB measuring technique. Finally, the subglottic area was surgically exposed allowing for direct caliper measurements of all four corresponding diameters. All three US measurements on each of the 62 rabbits and all four VB measurements on each of the 60 rabbits were compared with the gold standard corresponding caliper measurements. RESULTS: Statistical analysis revealed strikingly convergent values in subglottic lumen diameter measurements using US and calipers. The mean difference between these methods for all 186 observations was 0.11 mm. With 95% confidence, the maximum discordance was less than 0.30 mm on the smallest evaluated lumen. Convergent values were also demonstrated in subglottic lumen diameter measurements using VB and calipers. The mean difference between these methods for all 240 observations was 0.16 mm. With 95% confidence, the maximum discordance was less than 0.37 mm on the smallest evaluated lumen. Pearson's correlation coefficient supported a strong and positive relationship between US and caliper measurements as well as VB and caliper measurements. Simple linear regression model indicated that the subglottic lumen diameter could be predicted by both US and our VB technique. CONCLUSION: This work represents the first attempt to validate B-mode US and a VB technique as measuring tools for the subglottic lumen diameter. Our results have clearly shown that both methods are precise measuring modalities for this purpose. With further studies, these two objective methods of measuring the subglottic diameter could be adopted universally. The precise knowledge of this diameter could help physicians recognize and describe the severity of a narrowed lumen. Reporting results in such a standardized fashion, by either US or VB, could facilitate communication among clinicians and institutions.

Animals↗

PubMed2000

Web reports.

Explore the source record for details and available documents.

Critical Care↗

PubMed1999

Genetic polymorphisms in methylenetetrahydrofolate reductase and methionine synthase, folate levels in red blood cells, and risk of neural tube defects.

Folic acid administration to women in the periconceptional period reduces the occurrence of neural tube defects (NTDs) in their offspring. A polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR), 677C-->T, is the first genetic risk factor for NTDs in man identified at the molecular level. The gene encoding another folate-dependent enzyme, methionine synthase (MTR), has recently been cloned and a common variant, 2756A-->G, has been identified. We assessed genotypes and folate status in 56 patients with spina bifida, 62 mothers of patients, 97 children without NTDs (controls), and 90 mothers of controls, to determine the impact of these factors on NTD risk. Twenty percent of cases and 18% of case mothers were homozygous for the MTHFR polymorphism, compared to 11% of controls and 11% of control mothers, indicating that the mutant genotype conferred an increased risk for NTDs. The risk was further increased if both mother and child had this genotype. The MTR polymorphism was associated with a decreased O.R. (O.R.); none of the cases and only 10% of controls were homozygous for this variant. Red blood cell (RBC) folate was lower in cases and in case mothers, compared to their respective controls. Having a RBC folate in the lowest quartile of the control distribution was associated with an O.R. of 2.56 (95% CI 1.28-5.13) for being a case and of 3.05 (95% CI 1.54-6.03) for being a case mother. The combination of homozygous mutant MTHFR genotype and RBC folate in the lowest quartile conferred an O.R. for being a NTD case of 13.43 (CI 2.49-72.33) and an O.R. for having a child with NTD of 3.28 (CI 0.84-12.85). We propose that the genetic-nutrient interaction--MTHFR polymorphism and low folate status--is associated with a greater risk for NTDs than either variable alone.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed1999

A common variant in methionine synthase reductase combined with low cobalamin (vitamin B12) increases risk for spina bifida.

Impairment of folate and cobalamin (vitamin B(12)) metabolism has been observed in families with neural tube defects (NTDs). Genetic variants of enzymes in the homocysteine remethylation pathway might act as predisposing factors contributing to NTD risk. The first polymorphism linked to increased NTD risk was the 677C-->T mutation in methylenetetrahydrofolate reductase (MTHFR). We now report a polymorphism in methionine synthase reductase (MTRR), the enzyme that activates cobalamin-dependent methionine synthase. This polymorphorism, 66A-->G (I22M), has an allele frequency of 0.51 and increases NTD risk when cobalamin status is low or when the MTHFR mutant genotype is present. Genotypes and cobalamin status were assessed in 56 patients with spina bifida, 58 mothers of patients, 97 control children, and 89 mothers of controls. Cases and case mothers were almost twice as likely to possess the homozygous mutant genotype when compared to controls, but this difference was not statistically significant. However, when combined with low levels of cobalamin, the risk for mothers increased nearly five times (odds ratio (OR) = 4.8, 95% CI 1.5-15.8); the OR for children with this combination was 2.5 (95% CI 0.63-9.7). In the presence of combined MTHFR and MTRR homozygous mutant genotypes, children and mothers had a fourfold and threefold increase in risk, respectively (OR = 4.1, 95% CI 1.0-16.4; and OR = 2.9, 95% CI 0.58-14.8). This study provides the first genetic link between vitamin B(12) deficiency and NTDs and supports the multifactorial origins of these common birth defects. Investigation of this polymorphism in other disorders associated with altered homocysteine metabolism, such as vascular disease, is clearly warranted.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed1999

Adhesion-related small-bowel obstruction after gynecologic operations.

OBJECTIVE: Our purpose was to evaluate a possible relationship between adhesion-related small-bowel obstruction and gynecologic operations. STUDY DESIGN: The records of all female patients with the diagnosis of small-bowel obstruction from 1989 to 1996 were studied. The cause of bowel obstruction, the type and technique of previous operations, and whether the parietal peritoneum was closed at the completion of the procedure or was left open were evaluated. RESULTS: Among 262 women the most common cause of small-bowel obstruction was intra-abdominal adhesions (37.0%). Among 92 women with adhesion-related small-bowel obstruction, 35 women (38%) had undergone a previous abdominal hysterectomy. The incidence of small-bowel obstruction after an abdominal hysterectomy was 16.3 per 1000 hysterectomies. The incidence of small-bowel obstruction after cesarean delivery (5/10,000 cesarean deliveries) was significantly less than after other abdominal operations. Adhesions were found between the small bowel and the pelvis in 14 women (29.8%), and all were in women who had undergone a hysterectomy. In 33 others (70.2%) the adhesions were found between the previous abdominal incision and the intestine. The median interval between the initial operation and the small-bowel obstruction was 5.3 years. CONCLUSION: The most common cause of small-bowel obstruction is postsurgical adhesions. Adhesionrelated small-bowel obstruction is commonly found after an abdominal hysterectomy. Bowel obstruction can occur many years after the initial abdominal surgery.

Adnexal Diseases↗

PubMed1999

Family trauma and its association with emotional and behavioral problems and social adjustment in adolescent Cambodian refugees.

OBJECTIVE: The main aim of this study was to investigate the effect of war-related trauma on the subsequent social adjustment and functioning of young Cambodian refugees. METHOD: This longitudinal study of 67 young Cambodian refugees in Montreal interviewed in the first year of high school and then 2 years later examines a family's exposure to war related premigration trauma and its association with an adolescent's emotional and behavioral problems and social adjustment. Emotional and behavioral problems were assessed using the Youth Self-Report and an inventory of risk behavior. Social adjustment was assessed in terms of academic achievement, peer relations, and feeling of competence. RESULTS: The trauma a family suffered before leaving their homeland and prior to the teenager's birth seems to play a protective role at various times in adolescence with regard to externalized symptoms, risk behavior, and school failure in boys, and foster positive social adjustment in girls. CONCLUSIONS: These reactions may be understood as overcompensation by the children of the survivors of a massacre, to whom the implicit duty to succeed has been passed on. They suggest that a broader range of posttraumatic responses to war situations should be investigated and that trauma's dual nature as both burden and source of strength should be examined more closely.

Adolescent↗

PubMed1999

Effectiveness of antihyperlipidemic drug management in clinical practice.

Although randomized clinical trials have convincingly shown the efficacy of antihyperlipidemic drugs, both discontinuation of antihyperlipidemic drugs and failure to achieve goal lipid levels would be expected to attenuate the effect of these drugs on reducing the rates of hospitalization for coronary events. This study compares the rates of hospitalization and low-density lipoprotein cholesterol (LDL-C) levels during and after discontinuation of antihyperlipidemic drug therapy. A retrospective cohort study was conducted among 2369 patients at 2 health maintenance organizations (HMOs) during the period 1988 to 1994. Rates of coronary heart disease (CHD)-related hospitalization and non-CHD-related hospitalization and the LDL-C levels between 14 and 180 days after the initiation or discontinuation of drug therapy were compared for periods of antihyperlipidemic drug use and nonuse. The rate ratio for CHD hospitalization during periods of antihyperlipidemic drug use compared with periods of nonuse was 1.02 (95% CI, 0.74 to 1.40), excluding the first 6 months after initiation or discontinuation and controlling for patient sex, age, history of CHD, hypertension, diabetes, and HMO site. By contrast, the adjusted rate ratio was 0.70 (95% CI, 0.61 to 0.80) for non-CHD hospitalization. The percentage of patients with a history of CHD who achieved LDL-C levels <130 mg/dL was 27% < or =6 months after initiation of antihyperlipidemic drug therapy compared with 18% during gaps in drug therapy (P = 0.04). This study failed to demonstrate the effectiveness of lipid-lowering therapy in reducing CHD hospitalizations in community settings, apparently because most recipients either discontinued therapy or failed to achieve the desired LDL-C reduction while receiving therapy. These results indicate the need for interventions to improve patient compliance and management of lipid disorders.

Aged↗

PubMed1999

Utilization and cost of immunotherapy for allergic asthma and rhinitis.

BACKGROUND: Allergic rhinitis and asthma are important sources of morbidity among adults and children. Although immunotherapy is sometimes used to treat these conditions, there is little information on its use, adherence, or cost in the general population. OBJECTIVE: We sought to characterize the recipients of immunotherapy for allergic rhinitis and/or asthma with respect to their immunotherapy and utilization of health care services. METHODS: A combination of automated and manually extracted data was used to identify HMO members with diagnoses of allergic rhinitis or asthma who were treated with immunotherapy. Costs associated with immunotherapy and related care were examined by linear regression. Proportional hazards and Kaplan-Meier plots were used to evaluate duration of therapy. RESULTS: Of the 122,196 persons with a diagnosis of asthma or rhinitis, 2,667 were also treated with immunotherapy. Eligibility criteria were satisfied by 603 individuals who had 28,266 encounters for immunotherapy (median 48). Most patients (>80) were treated with multiple allergens; ragweed was the most common single allergen administered. Thirty-three percent of patients with sufficient observation time completed the intended course of 61 immunotherapy treatments. Females and younger patients had shorter durations of immunotherapy. The most common reason for discontinuation of therapy was patient's decision (54%). Immunotherapy costs were related most strongly to costs for care of rhinitis and asthma. Prescription drugs accounted for more than 50% of the non-immunotherapy costs; hospitalizations accounted for less than 20%. CONCLUSIONS: Approximately 2% of HMO members with an asthma or rhinitis diagnosis received immunotherapy. Although screened to optimize compliance, most patients did not complete immunotherapy. Costs of non-immunotherapy care were higher for individuals who completed immunotherapy which is consistent with more severe disease in this group.

Adolescent↗

PubMed1999

Efficient identification of postdischarge surgical site infections: use of automated pharmacy dispensing information, administrative data, and medical record information.

Although most surgical site infections (SSIs) occur after hospital discharge, there is no efficient way to identify them. The utility of automated claims and electronic medical record data for this purpose was assessed in a cohort of 4086 nonobstetric procedures following which 96 postdischarge SSIs occurred. Coded diagnoses, tests, and treatments were assessed by use of recursive partitioning, with 10-fold cross-validation, and logistic regression with bootstrap resampling. Specific codes and combinations of codes identified a subset of 2% of all procedures among which 74% of SSIs had occurred. Accepting a specificity of 92% improved the sensitivity from 74% to 92%. Use of only hospital discharge diagnosis codes plus pharmacy dispensing data had sensitivity of 77% and specificity of 94%. All of these performance characteristics were better than questionnaire responses from patients or surgeons. Thus, information routinely collected by health care systems can be the basis of an efficient, largely passive, surveillance system for postdischarge SSIs.

Algorithms↗

PubMed1999

Validation of patient reports, automated pharmacy records, and pill counts with electronic monitoring of adherence to antihypertensive therapy.

OBJECTIVES: To evaluate the validity of patient report, pharmacy dispensing records, and pill counts as measures of antihypertensive adherence using electronic monitoring as the validation standard. METHODS: The study was conducted among 286 members of Harvard Pilgrim Health Care, a managed care organization, who were at least 18 years of age, on monotherapy for hypertension, and had prescription drug coverage. Prescription refill adherence during the 12 months before enrollment was determined from their automated pharmacy dispensing records. Participants were interviewed about their medication adherence before and after a 3-month electronic monitoring period during which pill counts were also performed. Adherence to both recommended number and timing of doses was estimated from electronic monitoring data. Data analysis was based on statistical correlation and analysis of variance. RESULTS: Electronic adherence monitoring revealed that the proportion of prescribed doses consumed was higher (0.92) than the proportion of doses taken on time (0.63). The correlation between adherence to quantity and timing of doses was 0.32. Concurrent pill counts and earlier refilling patterns were moderately correlated with electronic monitoring (pill count: r = .52 with quantity and r = .17 with timing; refill adherence r = .32 with quantity and r = .22 with timing). There was considerable misclassification of adherence reported by patients, although nonadherence was generally accurately reported. CONCLUSIONS: Deviation from recommended timing of doses appears to be greater than from prescribed number of doses. Pharmacy dispensing records demonstrate predictive validity as measures of cumulative exposure and gaps in medication supply. Adherence levels determined from pill counts and pharmacy dispensing records correlate more closely with quantity than with timing of doses. Nonadherence reported by patients can serve as a qualitative indicator and predictor of reduced adherence.

Adolescent↗

PubMed1999

Resource utilization associated with initial hospital stays complicated by early onset group B streptococcal disease.

BACKGROUND: The epidemiology of early onset neonatal group B streptococcal (GBS) disease has changed appreciably, but there are no recent assessments of the in-hospital resource utilization it incurs. STUDY DESIGN: We performed a retrospective cohort study of infants delivered from 1987 through 1995 at Massachusetts' largest obstetrics hospital. A matched cohort design was used to assess care occurring after transfer to another acute care hospital. RESULTS: There were 135 cases of early onset neonatal GBS infection complicating 85,062 deliveries (1.6/1,000 births) in 9 years, with a substantial decline beginning in 1994, when maternal intrapartum chemoprophylaxis was widely introduced. Most (73%) infants had birth weights of 2500 g or more; 93% survived. Overall both the median and mean lengths of stay were 8 days longer for infants with GBS disease than for those without this infection (P < 0.001). Total hospital charges for neonates with GBS disease also were higher, with the difference in medians of $5323 and in means of $10,004 (P < 0.001). Differences were greatest among >2500-g birth weight infants; no excess was evident for infants with birth weights of < 1500 g. CONCLUSION: There was a substantial excess length of stay and charges associated with early onset neonatal GBS disease, although this was less than previously reported.

Cost of Illness↗

PubMed1999

Are all growth-restricted newborns created equal(ly)?

BACKGROUND: Previous etiologic studies have defined intrauterine growth restriction (IUGR) based on a single cutoff. OBJECTIVE: To assess the relative importance of known etiologic determinants for different degrees (mild versus severe) and timing (preterm versus term) of fetal growth restriction. DESIGN: Hospital-based cohort study. SETTING: Tertiary-care university hospital. PARTICIPANTS: Sixty-five thousand two hundred eighty inborn singleton infants without major congenital anomalies delivered between January 1, 1978 and March 31, 1996. MEASUREMENTS: Comparison of adjusted odds ratios (ORs) and 95% confidence intervals for mild IUGR (defined as birth weight 75% to <85% of the mean for gestational age, the latter cutoff equivalent to the 9.9th percentile for this cohort) and severe IUGR (<75% of mean, or 2.3rd percentile), after controlling for maternal age, education, marital status, and other potential determinants by means of multiple logistic regression. RESULTS: Maternal prepregnancy overweight (body mass index [BMI] >26.0-29.0 kg/m2) and obesity (BMI >29.0 kg/m2) had stronger protective effects against mild IUGR than against severe IUGR, but most of the determinants showed the opposite pattern. This was especially true for pathologic determinants; ORs (and 95% confidence intervals) for severe versus mild IUGR were 18.5 (14.5-23.8) vs 4.6 (3.6-5.8) for severe pregnancy-induced hypertension (PIH), 3.5 (2.2-5.5) vs 2.3 (1. 5-3.4) for prepregnancy hypertension, and 3.4 (2.9-3.9) vs 2.2 (2. 0-2.4) for smoking >/=11 cigarettes/day. Primiparity, short stature, prepregnancy BMI, maternal weight gain, and cigarette smoking had significantly larger effects on term IUGR, whereas the effect of severe PIH was more than twice as large for preterm IUGR (OR = 9.7 [7.3-13.0]) as for term IUGR (OR = 4.0 [3.0-5.3]). CONCLUSION: Pathologic determinants of IUGR such as prepregnancy and PIH and cigarette smoking predispose to more severe fetal growth retardation, and PIH in particular seems to do so before 37 weeks. Growth-restricted newborns are not, therefore, all created equal(ly).

Adult↗

PubMed1998

Secular trends in preterm birth: a hospital-based cohort study.

CONTEXT: Canada and the United States have reported a recent increase in the incidence of preterm birth, but the reasons for this increase are unknown. OBJECTIVE: To assess secular trends in preterm birth and its potential determinants. DESIGN: Hospital-based cohort study. SETTING: Canadian tertiary care university teaching hospital, 1978-1996. PARTICIPANTS: A total of 65574 nonreferred live births and stillbirths. MAIN OUTCOME MEASURES: Changes in occurrence of preterm birth, before and after adjustment for changes in method of gestational age assessment, obstetric intervention, registration of births weighing less than 500 g, and sociodemographic, behavioral, and clinical determinants. RESULTS: A crude secular increase in preterm births was seen for births less than 37, 34, and 32 completed weeks using 3 alternative gestational age estimation methods. Based on an algorithm incorporating both menstrual and early ultrasound gestational age estimates, rates increased from 6.6% to 9.8% for births at less than 37 weeks' gestation, 1.7% to 2.3% at less than 34 weeks, and 1.0% to 1.2% at less than 32 weeks. Exclusion of births weighing less than 500 g and those with induction or preterm cesarean delivery without labor before each of the corresponding gestational age cutoffs eliminated the secular trends for births before 34 and 32 weeks and attenuated the trend for births before 37 weeks. Nearly half of the remaining trend for births before 37 weeks was accounted for by the increasing use of early ultrasound dating. The residual trend was eliminated after controlling for secular increases in unmarried status and the proportion of women aged 35 years or older. These factors, combined with a decrease in alcohol consumption and increases in histological chorioamnionitis and cocaine use, appear to have counteracted a reduction in preterm birth since the mid-1980s that otherwise would have been observed. CONCLUSIONS: This hospital's increase in preterm births since 1978 parallels increases reported in population-based national studies from the United States and Canada. This trend appears largely attributable to the increasing use of early ultrasound dating, preterm induction and preterm cesarean delivery without labor, and changes in sociodemographic and behavioral factors.

Canada↗

PubMed1998

Determinants of preterm birth rates in Canada from 1981 through 1983 and from 1992 through 1994.

BACKGROUND: The rates of preterm birth have increased in many countries, including Canada, over the past 20 years. However, the factors underlying the increase are poorly understood. METHODS: We used data from the Statistics Canada live-birth and stillbirth data bases to determine the effects of changes in the frequency of multiple births, registration of births occurring very early in gestation, patterns of obstetrical intervention, and use of ultrasonographic dating of gestational age on the rates of preterm birth in Canada from 1981 through 1983 and from 1992 through 1994. All births in 9 of the 12 provinces and territories of Canada were included. Logistic-regression analysis and Poisson regression analysis were used to estimate changes between the two three-year periods, after adjustment for the above-mentioned determinants of the likelihood of preterm births. RESULTS: Preterm births increased from 6.3 percent of live births in 1981 through 1983 to 6.8 percent in 1992 through 1994, a relative increase of 9 percent (95 percent confidence interval, 7 to 10 percent). Among singleton births, preterm births increased by 5 percent (95 percent confidence interval, 3 to 6 percent). Multiple births increased from 1.9 percent to 2.1 percent of all live births; the rates of preterm birth among live births resulting from multiple gestations increased by 25 percent (95 percent confidence interval, 21 to 28 percent). Adjustment for the determinants of the likelihood of preterm birth reduced the increase in the rate of preterm birth to 3 percent among all live births and 1 percent among singleton births. CONCLUSIONS: The recent increase in preterm births in Canada is largely attributable to changes in the frequency of multiple births, obstetrical intervention, and the use of ultrasound-based estimates of gestational age.

Birth Rate↗

PubMed1998

Lamotrigine and severe skin eruptions.

Lamotrigine is an important new addition to the drugs used to treat people with seizure disorders, but disconcerting are reports of a higher than expected incidence of severe skin reaction among children. Using automated data from three HMOs, we conducted a retrospective investigation of children (<15 years) exposed to lamotrigine from 1 January 1995 to 30 June 1997. The outcome of interest was hospitalization for a severe skin reaction (e.g. erythema multiforme). Lamotrigine was dispensed to 124 children (56% female, mean age 8.7 years); the mean number of dispensings per person was 10. Of those exposed, 59 (47%) were hospitalized at least once during the study period, mainly for convulsions and epilepsy. There were no hospitalizations for or with a diagnosis of severe skin reactions. Our investigation revealed no evidence to support a causal relationship between lamotrigine and severe skin reactions. However, because our sample size was small we had power to detect only a very strong association between lamotrigine and severe skin disease. Taken alone, our study does not establish the risks of lamotrigine. These results should be viewed as a contribution to the totality of evidence that will be used to assess the safety of lamotrigine.

Journal Article↗

PubMed1998

Limulus amebocyte lysate assay for detection of endotoxin in patients with sepsis syndrome. AMCC Sepsis Project Working Group.

Clinical predictions alone are insufficiently accurate to identify patients with specific types of bloodstream infection; laboratory assays might improve such predictions. Therefore, we performed a prospective cohort study of 356 episodes of sepsis syndrome and did Limulus amebocyte lysate (LAL) assays for endotoxin. The main outcome measures were bacteremia and infection due to gram-negative organisms; other types of infection were secondary outcomes. Assays were defined as positive if the result was > or = 0.4 enzyme-linked immunosorbent assay units per milliliter. There were positive assays in 119 (33%) of 356 episodes. Assay positivity correlated with the presence of fungal bloodstream infection (P < .003) but correlated negatively with the presence of gram-negative organisms in the bloodstream (P = .04). A trend toward higher rates of mortality in the LAL assay-positive episodes was no longer present after adjusting for severity. Thus, results of LAL assay did not correlate with the presence of bacteremia due to gram-negative organisms or with mortality after adjusting for severity but did correlate with the presence of fungal bloodstream infection.

Bacteremia↗

PubMed1998

Use of antibiotic exposure to detect postoperative infections.

OBJECTIVE: To assess the utility of postoperative antibiotic exposure as an indicator of postoperative infection after coronary artery bypass graft surgery. DESIGN: We determined an optimal antibiotic exposure threshold by creating receiver operating characteristic curves. SETTING: Tertiary healthcare institution (United States); national sample (Israel). PATIENTS: 5,887 patients undergoing coronary artery bypass graft surgery. RESULTS: Postoperative antibiotic exposure with at least 9 days between the first and last dates of antibiotic administration, excluding the first postoperative day, had a sensitivity of 95% (261/276) and specificity of 85% (3,944/4,628) for identifying surgical-site infection, using as a gold standard surgical-site infections identified by conventional prospective surveillance or extrapolated from review of a sample of medical records. In contrast, using the same gold standard for surgical-site infections, the sensitivity of routine prospective surveillance alone was only 60%. The predictive value positive of the defined antibiotic exposure was 28% (261/945) for surgical-site infection and 60% (563/945) for any nosocomial infection. In the Israeli cohort, the sensitivity was 87% (74/85) and the specificity was 82% (735/898). CONCLUSION: Antibiotic exposure of sufficient duration and timing was more sensitive than conventional methods in detecting nosocomial infection and required substantially less effort to collect. Although the predictive value positive for surgical-site infection was only moderate, the majority of individuals identified this way had a nosocomial infection.

Antibiotic Prophylaxis↗