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Observational Cohort (observational + cohort)

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Medical Sciences100%

Terms modified by Observational Cohort

  • observational cohort study
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    Selected Abstracts

    Telemetry Monitoring during Transport of Low-risk Chest Pain Patients from the Emergency Department: Is It Necessary?

    ACADEMIC EMERGENCY MEDICINE, Issue 10 2005
    Adam J. Singer MD
    Abstract Background: Low-risk emergency department (ED) patients with chest pain (CP) are often transported by nurses to monitored beds on telemetry monitoring, diverting valuable resources from the ED and delaying transport. Objectives: To test the hypothesis that transporting low-risk CP patients off telemetry monitoring is safe. Methods: This was a secondary analysis of a prospective, observational cohort of ED patients with low-risk chest pain (no active chest pain, normal or nondiagnostic electrocardiogram, normal initial troponin I) admitted to a non,intensive care unit monitored bed who were transported off telemetry monitor by nonclinical personnel. A protocol allowing transportation of low-risk CP patients off telemetry monitoring to a monitored bed was developed, and an ongoing daily log of patients transported off telemetry was maintained for the occurrence of any adverse events en route to the floor. Adverse events requiring treatment included dysrhythmias, hypotension, syncope, and cardiac arrest. The study population included patients who presented during September,October 2004, whose data were abstracted from the medical records using standardized methodology. A subset of 10% of the medical records were reviewed by a second investigator for interrater reliability. Death, syncope, resuscitation, and dysrhythmias during transport or immediately on arrival to the floor were the outcomes measured. Descriptive statistics and confidence intervals (CIs) were used in data analysis. Results: During the study period, 425 patients had CP of potentially ischemic origin, of whom 322 (75.8%) were low risk and met the inclusion criteria and were transported off monitors. Their mean (±standard deviation) age was 58.3 (±16.0) years; 48.1% were female. During transport from the ED, there was no patient with any adverse events requiring treatment and there was no death (95% CI = 0% to 0.93%). Conclusions: Transportation of low-risk ED chest pain patients off telemetry monitoring by nonclinical personnel to the floor appears safe. This may reduce diversion of ED nurses from the ED, helping to alleviate nursing shortages. [source]

    The Multicenter Study of Epilepsy Surgery: Recruitment and Selection for Surgery

    EPILEPSIA, Issue 11 2003
    Anne T. Berg
    Summary:,Purpose: Multiple studies have examined predictors of seizure outcomes after epilepsy surgery. Most are single-center series with limited sample size. Little information is available about the selection process for surgery and, in particular, the proportion of patients who ultimately have surgery and the characteristics that identify those who do versus those who do not. Such information is necessary for providing the epidemiologic and clinical context in which epilepsy surgery is currently performed in the United States and in other developed countries. Methods: An observational cohort of 565 surgical candidates was prospectively recruited from June 1996 through January 2001 at six Northeastern and one Midwestern surgical centers. Standardized eligibility criteria and protocol for presurgical evaluations were used at all seven sites. Results: Three hundred ninety-six (70%) study subjects had resective surgery. Clinical factors such as a well-localized magnetic resonance imaging (MRI) abnormality and consistently localized EEG findings were most strongly associated with having surgery. Of those who underwent intracranial monitoring (189, 34%), 85% went on to have surgery. Race/ethnicity and marital status were marginally associated with having surgery. Age, education, and employment status were not. Demographic factors had little influence over the surgical decision. More than half of the patients had intractable epilepsy for ,10 years and five or more drugs had failed by the time they initiated their surgical evaluation. During the recruitment period, eight new antiepileptic drugs were approved by the Food and Drug Administration for use in the United States and came into increasing use in this study's surgical candidates. Despite the increased availability of new therapeutic options, the proportion that had surgery each year did not fluctuate significantly from year to year. This suggests that, in this group of patients, the new drugs did not provide a substantial therapeutic benefit. Conclusions: Up to 30% of patients who undergo presurgical evaluations for resective epilepsy surgery ultimately do not have this form of surgery. This is a group whose needs are not currently met by available therapies and procedures. Lack of clear localizing evidence appears to be the main reason for not having surgery. To the extent that these data can address the question, they suggest that repeated attempts to control intractable epilepsy with new drugs will not result in sustained seizure control, and eligible patients will proceed to surgery eventually. This is consistent with recent arguments to consider surgery earlier rather than later in the course of epilepsy. Postsurgical follow-up of this group will permit a detailed analysis of presurgical factors that predict the best and worst seizure outcomes. [source]

    Cost-effectiveness of HIV nonoccupational post-exposure prophylaxis in Australia

    HIV MEDICINE, Issue 4 2009
    D Guinot
    Objective The aim of the study was to determine the cost-effectiveness of HIV nonoccupational post-exposure prophylaxis (NPEP) in Australia. Methods A retrospective cost analysis of a population-based observational cohort of 1601 participants eligible for NPEP in Australia between 1998 and 2004 was carried out. We modelled NPEP treatment costs and combined them with effectiveness outcomes to calculate the cost per seroconversion avoided. We estimated the cost-utility of the programme, and sensitivity and threshold analysis was performed on key variables. Results The average NPEP cost per patient was A$1616, of which A$848 (52%) was for drugs, A$331 (21%) for consultations, A$225 (14%) for pathology and A$212 (13%) for other costs. The cost per seroconversion avoided in the cohort was A$1 647 476 in our base case analysis, and A$512 410 when transmission rates were set at their maximal values. The cost per quality-adjusted life-year (QALY) was between A$40 673 and A$176 772, depending on the risks of HIV transmission assumed. Conclusions In our base case, NPEP was not a cost-effective intervention compared with the widely accepted Australian threshold of A$50 000 per QALY. It was only cost-effective after receptive unprotected anal intercourse exposure to an HIV-positive source. Although NPEP was a relatively well-targeted intervention in Australia, its cost-effectiveness could be improved by further targeting high-risk exposures. [source]

    Not Another Formula for Heart Rate Correction of QT Interval

    ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2009
    F.R.C.P., Peter J. Bourdillon M.B.B.S.
    Background: Normal limits for QT and heart rate were developed in a Japanese population undergoing 24 hour recordings of the electrocardiogram (ECG). The purpose of this study is to validate these normal limits in a West London population having 12-lead ECGs. Methods: A retrospective observational cohort of 10,099 patients aged 20,79 attending a hospital ECG department was studied. From the Japanese data z-scores were calculated for men under 50, for men over 50, for women under 50 and for women over 50. z-scores were used to compare the West London and Japanese populations. Results: Cardiac infarction injury scores (CIIS) for all four groups were less than zero indicating a population at low risk of cardiovascular disease. From the Japanese data a z-score of 1 is roughly 20 ms. West London mean (SD) z-scores for men under 50, for men over 50, for women under 50 and for women over 50 were 0.20 (0.85), ,0.02 (0.86), 0.14 (0.93), and ,0.45 (0.88), respectively. Conclusions: The distributions of the QT and heart rate data of a West London population at low risk of cardiovascular disease are comparable to the Japanese data. The Japanese QT normal limits for women over the age of 50 are about 9 ms higher regardless of heart rate. The QT normal limits for Afro-Caribbeans are about 5 ms lower than other ethnic groups. The Japanese normal limits are applicable elsewhere, albeit adjusting for women over the age of 50 and for Afro-Caribbeans. [source]

    Low vitamin K status is associated with osteoarthritis in the hand and knee,

    ARTHRITIS & RHEUMATISM, Issue 4 2006
    Tuhina Neogi
    Objective Poor intake of vitamin K is common. Insufficient vitamin K can result in abnormal cartilage and bone mineralization. Furthermore, osteophyte growth, seen in osteoarthritis (OA), may be a vitamin K,dependent process. We undertook this study to determine whether vitamin K deficiency is associated with radiographic features of OA. Methods We conducted an analysis among 672 participants (mean age 65.6 years, 358 women) in the Framingham Offspring Study, a population-based prospective observational cohort. Levels of plasma phylloquinone (the primary form of vitamin K) had previously been measured in these participants, for whom we also had bilateral hand and knee radiographs. The main outcomes were 1) prevalence ratios (PRs) of OA, osteophytes, and joint space narrowing (JSN) per quartile of plasma phylloquinone level for each joint, adjusting for correlated joints using generalized estimating equations, and 2) adjusted mean number of joints with each feature per quartile of plasma phylloquinone level. Analyses were conducted in hands and knees separately and adjusted for age, sex, body mass index, total energy intake, plasma vitamin D, and femoral neck bone mineral density. Results The PRs for OA, osteophytes, and JSN and adjusted mean number of joints with all 3 features in the hand decreased significantly with increasing plasma phylloquinone levels (P , 0.03 for all). For example, as plasma phylloquinone levels rose, the PR for hand OA decreased from 1.0 to 0.7 (P = 0.005). For the knee, only the PR for osteophytes and the adjusted mean number of knee joints with osteophytes decreased significantly with increasing plasma phylloquinone levels (PR decreased from 1.0 to 0.6, P = 0.01). Conclusion These observational data support the hypothesis of an association between low plasma levels of vitamin K and increased prevalence of OA manifestations in the hand and knee. [source]

    Fetal inflammatory response in women with proteomic biomarkers characteristic of intra-amniotic inflammation and preterm birth

    BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 2 2009
    CS Buhimschi
    Objective, To determine the relationship between presence of amniotic fluid (AF) biomarkers characteristic of inflammation (defensins 2 and 1 and calgranulins C and A) and fetal inflammatory status at birth. Design, Prospective observational cohort. Setting, Tertiary referral University hospital. Population, One hundred and thirty-two consecutive mothers (gestational age, median [interquartile range]: 29.6 [24.1,33.1] weeks) who had a clinically indicated amniocentesis to rule out infection and their newborns. Methods, Intra-amniotic inflammation was diagnosed by mass spectrometry surface-enhanced-laser-desorption-ionization time of flight (SELDI-TOF). The AF proteomic fingerprint (mass-restricted [MR] score) ranges from 0,4 (none to all biomarkers present). The intensity of intra-amniotic inflammation was graded based on the number of proteomic biomarkers: MR score 0: ,no' inflammation, MR score 1,2: ,minimal' inflammation and MR score 3,4: ,severe' inflammation. At birth, cord blood was obtained for all women. Severity of histological chorioamnionitis and early-onset neonatal sepsis (EONS) was based on established histological and haematological criteria. Interleukin-6 (IL-6) levels were measured by sensitive immunoassays. The cord blood-to-AF IL-6 ratio was used as an indicator of the differential inflammatory response in the fetal versus the AF compartment. Main outcome measures, To relate proteomic biomarkers of intra-amniotic infection to cord blood IL-6 and to use the latter as the primary marker of fetal inflammatory response. Results, Women with intra-amniotic inflammation delivered at an earlier gestational age (analysis of variance, P < 0.001) and had higher AF IL-6 levels (P < 0.001). At birth, neonates of women with severe intra-amniotic inflammation had higher cord blood IL-6 levels (P = 0.002) and a higher frequency of EONS (P = 0.002). EONS was characterised by significantly elevated cord blood IL-6 levels (P < 0.001). Of the 39 neonates delivered by mothers with minimal intra-amniotic inflammation, 15 (39%) neonates had umbilical cord blood IL-6 levels above the mean for the group and 2 neonates had confirmed sepsis. The severity of the neutrophilic infiltrate in the chorionic plate (P < 0.001), choriodecidua (P = 0.002), umbilical cord (P < 0.001) but not in the amnion (P > 0.05) was an independent predictor of the cord blood-to-AF IL-6 ratio. Relationships were maintained following correction for gestational age, birthweight, amniocentesis-to-delivery interval, caesarean delivery, status of the membranes, race, MR score and antibiotics and steroid exposure. Conclusions, We provide evidence that presence of proteomic biomarkers characteristic of inflammation in the AF is associated with an increased inflammatory status of the fetus at birth. Neonates mount an increased inflammatory status and have positive blood cultures even in the context of minimal intra-amniotic inflammation. [source]