Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “corrective measures”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2002

Corrections to measured sample pressures in low temperature collisional cooling experiments.

Three different thermal transpiration models have been tested for a range of pressures and temperatures normally encountered in collisional cooling experiments. The calculated corrections for two of these models follow similar patterns and differ only in magnitude at a fixed sample temperature for sample pressures between 0 and 8 Torr. Corrections calculated from the third model follow a pattern similar to the other two models only at pressures above about two Torr.

Cold Temperature↗
PubMed1991

[A utilization review program of cefoxitin].

A drug utilization review program of cefoxitin was conducted in a 714-bed teaching hospital. Health records of all 43 in-patients who received cefoxitin during the month of November 1987 were reviewed retrospectively. The use of cefoxitin (47 courses) was evaluated on the basis of "appropriate use" criteria developed from the literature and the physician's clinical experience. Of the 47 courses evaluated, cefoxitin was prescribed for prophylaxis in 47%, and its use was considered inappropriate in 86% of these. Overall, 66% of total cefoxitin usage was deemed inappropriate in this hospital. The cost associated with inappropriate use was estimated at $2672 for the period of the study. Corrective measures were then implemented to rectify the identified problems. A second study was conducted 2 years later to assess the impact of the corrective measures. This utilization review program of cefoxitin showed that optimal use of a drug requires not only close collaboration between pharmacists and physicians but a continuous and not a sporadic process of surveillance of the prescription for the drug being studied.

Bacterial Infections↗
PubMed1997

Regression calibration method for correcting measurement-error bias in nutritional epidemiology.

Regression calibration is a statistical method for adjusting point and interval estimates of effect obtained from regression models commonly used in epidemiology for bias due to measurement error in assessing nutrients or other variables. Previous work developed regression calibration for use in estimating odds ratios from logistic regression. We extend this here to estimating incidence rate ratios from Cox proportional hazards models and regression slopes from linear-regression models. Regression calibration is appropriate when a gold standard is available in a validation study and a linear measurement error with constant variance applies or when replicate measurements are available in a reliability study and linear random within-person error can be assumed. In this paper, the method is illustrated by correction of rate ratios describing the relations between the incidence of breast cancer and dietary intakes of vitamin A, alcohol, and total energy in the Nurses' Health Study. An example using linear regression is based on estimation of the relation between ultradistal radius bone density and dietary intakes of caffeine, calcium, and total energy in the Massachusetts Women's Health Study. Software implementing these methods uses SAS macros.

Adult↗
PubMed2001

[Quality assurance program for blood products in an out-of-hospital medical care unit].

INTRODUCTION: Transfusion of blood products is part of out-of-hospital medical activity. Despite rare use of transfusion and difficult environment, the rules of transfusion must be respected: follow up to detect blood products, security, and patient's information before and after transfusion, follow up of infectious and immunological consequences. However, the current law and usable documents were not conceived for out-of-hospital emergency care. OBJECTIVE: To improve follow-up of blood product transfusion in out-of-hospital medical care (Smur). STUDY DESIGN: Quality assurance programme. MATERIAL AND METHODS: a) Initial evaluation with a retrospective analysis based on the medical chart of patient for whom transfusion has been performed; b) corrective measures were proposed with creation of a specific document concerning transfusion and guidelines for blood product delivery in the out-of-hospital emergency care; c) evaluation of the impact of these correctives measures. RESULTS: Less than one per cent of patients treated by our Smur needed transfusion, mainly during interhospital transfer. Patients were in a life-threatening situation in 50% of cases. Follow-up improved after implementation of the programme from 25 to 83% of transfused patient (p < 0.001). Despite limitation due to the small number of patients, other parameters also improved. CONCLUSION: The use of specific guidelines and document improves the follow-up of transfusion in out-of-hospital medical care.

Adolescent↗
PubMed1988

Relationship of lung function loss to level of initial function: correcting for measurement error using the reliability coefficient.

The regression of lung function change on the initial lung function level is biased when the initial level is measured with random error. Several methods have been proposed to obtain unbiased estimates of regression coefficients in such circumstances. We apply these methods to examine the relationship between lung function loss over 11 years and its initial level in 433 men aged about 20 when first seen. On theoretical and practical grounds the best method is the correction of the regression coefficient using the reliability coefficient. This is defined as the ratio of the error free variance to the variance of the variable measured with error, and is easily estimated as the correlation between repeat measurements of the underlying level. In young men the loss of some lung functions (forced vital capacity [FVC], forced expiratory volume in one second [FEV1], forced expiratory flow in the middle half of expiration, and the ratio FEV1/FVC) do not appear to be related to initial level.

Adult↗
PubMed1998

Calculation of exposure chamber leak rate with thermal correction: a measure of chamber integrity.

A method for assessing inhalation exposure chamber integrity by calculation of leak rate was modified to account for temporal changes of temperature in the chamber. In a well-sealed chamber, accounting for thermal effect brought observed leak rates into better agreement with predicted values. Mean estimates of chamber leak rate without thermal correction ranged from 2.9 to 40.6 cm3/min whereas those with thermal correction ranged from 9.6 to 14.3 cm3/min. The average change in estimate of chamber leak rate brought about by correcting for thermal effect was 16.8 cm3/min per K change of temperature in the chamber. Accounting for thermal effect reduced the coefficient of variation for repeated estimates (n = 10) of chamber leak rate from 65 to 15%. The use of temperature-corrected calculation of chamber leak rate minimizes thermal artifact thereby improving decisions about chamber operation based on assessment of chamber integrity.

Air Pollutants, Occupational↗
PubMedDate not supplied

[Control of respiratory monitoring in the critical patient].

This study of the safety of patients undergoing mechanical ventilation was undertaken to ensure correct ventilation and to find quality-control elements for patients and nursing staff. Differences in mode programming and ventilation parameters and their registry at the change of nursing shifts, and correct programming of the sensitivity and minimum minute volume alarms and maximum airway pressure alarms were examined. In a two-month period, 8 cross-sectional studies were made of G1 prevalence in each of three nursing shifts. The status of the alarms and sensitivity were recorded when incorrect, as well as whether the ventilation mode and parameters coincided with the change of nursing shift. An analysis was made of: FiO2, PEEP, respiratory rate, minute volume, tidal volume, support pressure level, and control pressure level depending on the ventilation mode. Corrective measures were applied for a month. The effectiveness of these measures was evaluated by making 8 new G2 cross-sectional studies of the same type. Two hundred forty-eight G1 and 250 G2 recordings were made. The G2 studies revealed a generalized reduction in errors for all parameters. We concluded that the corrective measures were effective so these indicators were included in the monitoring of risk areas in the unit quality control program.

Critical Care↗
PubMed1993

[Intervention for improving the quality of antibiotic prescription in a basic health area].

OBJECTIVE: To evaluate the effectiveness of corrective measures introduced in a health area (HA) to improve the way antibiotics (AB) are prescribed. DESIGN: Intervention study, with a control. SITE. Two HAs: Cervera and Tarrega. The intervention was carried out in the first; the second serving as the control group. PATIENTS OR OTHER PARTICIPANTS: All the doctors in both areas' primary care teams (PCT). INTERVENTION: Monographic sessions of the PCT during June and October, 1991, analysed consecutively the following, which had taken place in the health area during 1990: the quality control methodology applied to the prescription; the quality indicators in the prescription--among them its classification by intrinsic value (IV)--; and the general level of prescription with the proportion of ABs prescribed. MAIN MEASUREMENTS AND RESULTS: The pharmaceutical listing of the 100 most prescribed drugs in relation to the number of containers were used as a data source for evaluating the November, 1990, AB prescription; with a re-evaluation in November, 1991, after the introduction of the corrective measures. Significant reductions could be observed in the health area where the intervention took place, both in the percentage of low IV drugs prescribed (-10.8%) and of intramuscular injections used (-23.5%). In the area used as the control group, there were no variations. CONCLUSIONS: The effect of the intervention on the improvement in the way ABs were prescribed, was clear.

Anti-Bacterial Agents↗
PubMed2001

Correcting for measurement error in binary and continuous variables using replicates.

Measurement error in exposures and confounders leads to bias in regression coefficients. It is possible to adjust for this bias if true values or independent replicates are observed on a subsample. We extend a method suitable for quantitative variables to the situation where both binary and quantitative variables are present. Binary variables with independent replicates introduce two extra problems: (i) the error is correlated with the true value, and (ii) the measurement error probabilities are unidentified if only two replicates are available. We show that - under plausible assumptions - adjustment for error in binary confounders does not need to address these problems. The regression coefficient for a binary exposure is overadjusted if methods for continuous variables are used. Correct adjustment is possible either if three replicates are available, or if further assumptions can be made; otherwise, bounds can be put on the correctly adjusted value, and these bounds are reasonably close together if the exposure has prevalence near 0.5.

Bias↗
PubMed1984

Investigation of energy responses of germanium detectors and correction of measured spectra by means of Monte Carlo simulation.

A Monte Carlo program was developed which determines the energy response of X-ray detectors of various "nested" sizes simultaneously. Twenty-one planar germanium detectors with cylindrical crystals were chosen, which are commercially available for X-ray spectrometry. The photopeak efficiency, K alpha and K beta escape fractions. Compton fraction, elastic fraction, penetration fraction, and the Compton continuum were tabulated as a function of incident X-ray energies from 12 to 300 keV in 2-keV increments. Coefficients of polynomials fitted to the Compton continua were also calculated to facilitate computer implementation of spectrum corrections. Spectrum correction methods which use the Compton continua determined by Monte Carlo calculation were compared with those approximated by rectangles. Comparison of the residual root-mean-square (RRMS) values between the incident and corrected spectra showed that the former method yielded lower RRMS values. However, the differences in these values are small, indicating that the simple rectangular approximation may be adequate for most spectral measurements.

Germanium↗
PubMedDate not supplied

[Managing methotrexate toxicity: a case report].

High-dose methotrexate is included in chemotherapy regimens used to treat a number of malignant neoplasms. Methotrexate plasma concentration is considered the best toxicity predictor. Monitoring methotrexate plasma concentrations is standard practice in the identification of at-risk patients, the titration of folinic acid doses, and the establishment of corrective measures. Methotrexate is a kidney-cleared weak acid, and renal function impairment may retard methotrexate clearance. A case of severe methotrexate-induced toxicity secondary to renal failure is reported in a patient with non-Hodgkin s lymphoma receiving methotrexate at a dose of 1 g/m2. Corrective measures included folinic acid rescue therapy, cholestyramine resin administration, hydration and urine alkalinization, urine pH monitoring, and extracorporeal clearance techniques.

Acute Kidney Injury↗
PubMedDate not supplied

Enhancing recovery of endocervical component on gynecologic cytology specimens processed by thin-layer technology.

OBJECTIVE: To address the causes and report the corrective measures required for resolving the initial problem of high rates of cervical vaginal cytology specimens reported as having no endocervical component on SurePath (AutoCyte, Inc., Burlington, North Carolina, U.S.A.) liquid-based, thin-layer technology at an academic center cytology laboratory. STUDY DESIGN: Analysis of 511 cases lacking endocervical/transformation zone component out of 9,221 SurePath thin-layer gynecologic specimens processed in a one-year period. The study encompassed a review of sample collection techniques by physicians and nurses, specimen processing, cytologic features of endocervical/squamous metaplastic cells processed by the SurePath method and statistical analysis of endocervical cell recovery rates after implementation of corrective measures. RESULTS: Absence of endocervical/transformation zone component varied from an initial 18% in the first month to an average of 5.3% after corrective actions were implemented. Current rates of SurePath thin-layer specimens having no endocervical component are lower than those for conventional smears. CONCLUSION: Since SurePath was only recently introduced to the market, there are no previously published data addressing how to optimize the recovery of endocervical component on liquid-based, thin-layer specimens processed by this methodology.

Cervix Uteri↗
PubMed1987

Prediction of arterial blood gases by transcutaneous O2 and CO2 in critically ill hyperdynamic trauma patients.

The management of severe adult respiratory distress syndrome in critically injured patients requires the frequent measurement of arterial blood gases for adjustment of cardiovascular and ventilatory support. Since these require blood withdrawal and laboratory determinations, a noninvasive method of assessment of arterial gas tensions would permit more frequent assessment of the patient as well as permitting rapid changes in the patient's ventilatory status to be detected earlier in the clinical course. The role of transcutaneous O2 and CO2 tension in providing these measurements was evaluated in 92 studies in 38 critically ill patients with ARDS due to trauma and/or sepsis. All patients were normodynamic or hyperdynamic at the time of study (cardiac index 2.5 to 7.6 L/min/m2) and were intubated and on increased inspired oxygen fractions (FIO2 = 30 to 100%) delivered by mechanical ventilation, had a range of body temperature from 35.0 to 39.5 degrees C and pH from 7.29 to 7.57 The data from a transcutaneous O2 and CO2 sensor applied to the skin of the anterior thorax were analyzed by multiple regression analysis of variances. Prediction of the arterial oxygen tension (PaO2) from 52 to 253 torr was possible from regression-corrected measurements of the transcutaneous O2 (TcO2): [PaO2 = 1.1 (TcO2) - 0.28 (FIO2) + 45.5]. The arterial carbon dioxide tension (PaCO2) from 26 to 57 torr was predicted from the transcutaneous CO2 (TcCO2):[PaCO2 = 0.76 (TcCO2) + 0.06 (FIO2) + 0.035 (TcO2) + 4.1]. With these corrections, a noninvasive Respiratory Index was computed for assessing ARDS severity, and dynamic changes in arterial gases could be followed in response to postural changes, ventilatory alterations, or cardiovascular perturbations. These data suggest that a reasonable estimate of the arterial blood gases can be obtained from a regression-corrected measurement of the transcutaneous O2 and CO2 tensions in critically injured normodynamic or hyperdynamic ARDS patients.

Adult↗
PubMed2001

[Quality control of the monitoring of normal pregnancy in primary care].

OBJECTIVES: GENERAL: to increase the quality of mother-baby care in our population. SPECIFIC: to improve by at least 10% the record of activities with poorest compliance at the first evaluation on the quality cycle. DESIGN: Quality cycle of the normal pregnancy monitoring programme in primary care (PC). The scientific-technical dimension of quality was the one studied. There was a retrospective, crossed evaluation, on internal initiative, about the clinical records of the pregnant women. SEQUENCE: first evaluation of pregnancies in 1994-95; application of corrective measures in 1996; second evaluation of pregnancies in 1997-98. SETTING: Primary care. PATIENTS: All the pregnancies monitored by our PC team during the periods described. MEASUREMENTS AND MAIN RESULTS: CRITERIA EVALUATED: care activities of the programme for monitoring normal pregnancies in Area 10. First evaluation (n = 54): 11.5% overall non-compliance. The criteria with under 80% compliance were: folic acid supplement, counselling, diagnosis of pregnancy diabetes and attendance in the month after delivery. Second evaluation (n = 69): 6.3% overall non-compliance. All activities surpassed 80% compliance except obstetric examination on the first visit, attendance a week after delivery and attendance a month after delivery. CONCLUSIONS: After introducing certain simple corrective measures, we achieved overall improvement of over 40% and increased compliance in most activities, except for attendance after delivery and obstetric examination on the first visit. We think a continuous cycle of quality improvement needs to be maintained in order to achieve adequate mother-baby care.

Cross-Sectional Studies↗
PubMed2004

[Value of various MR sequences using 1.5 and 3.0 Tesla in analyzing cartilaginous defects of the patella in an animal model].

PURPOSE: Comparison of MRI and macropathologic evaluation using various sequences and field strengths in the detection, localization and measurement of cartilage defects in an animal model. MATERIALS AND METHODS: After open creation of retropatellar cartilage defects of various widths, depths and locations in 8 cadaveric sheep knee joints, the knees were examined using a fat-suppressed (FS), proton density-weighted (PD) fast spin echo (FSE), and 2D and 3D gradient echo (GE) sequences on 1.5 T and 3.0 T MR scanners. The images were analyzed by two independent radiologists in a blinded manner, by dividing the patella into 15 virtual segments. The results were correlated with the macropathologic findings with regards to location, width, and depth of the defects. RESULTS: The highest sensitivity (67.1 %), diagnostic accuracy (85.4 %), positive (87.3 %), and negative (84.7 %) predictive values in detecting defects were obtained using the 3.0 T FS-3D-GE sequence. The highest specificity (95.6 %) yielded the 3.0 T FS-2D-GE sequence, with the other sequences inferior by no more than 2.6 %. In general, FS-3D-GE sequences were superior to FS-2D-GE (3.0 T: p < 0.05; 1.5 T: p < 0.05) and especially to FS-PD-FSE sequences (3.0 T: p < 0.01; 1.5 T: p < 0.05). In determining the defects' widths, the 3.0 T FS-3D-GE sequence was superior to all other sequences (correct measurements: 50.0 %), with only slight superiority to the 1.5 T FS-3D-GE sequence (46.9 %, p > 0.05) but clear superiority to the other sequences (28.1 - 40.6 %, vs. 1.5 T FS-PD-FSE: p < 0.05, vs. other sequences: p > 0.05). To determine the defects' depths, the 1.5 T FS-3D-GE sequence was most reliable (correct measurements: 53.1 %), followed by the 3.0 T FS-3D-GE sequence (50.0 %, significance of difference: p > 0.05). CONCLUSION: In detecting cartilage defects, the field strength of 3.0 Tesla was only superior to 1.5 T MRI using fat-saturated 3D- or 2D-GE-sequences but not in fat-saturated proton density-weighted SE-sequences. In determination of depth and length of the defects, the higher field strength was not advantageous.

Adult↗
PubMed2006

Association of indoor nitrogen dioxide with respiratory symptoms in children: application of measurement error correction techniques to utilize data from multiple surrogates.

In 1991, Neas et al. reported that indoor nitrogen dioxide (NO(2)), a byproduct of high-temperature combustion, was significantly associated with lower respiratory symptoms among a cohort of 1,159 white children aged 7-11 years in six US cities studied from 1983 to 1988. For each 15 p.p.b. increment of NO(2), the multivariate adjusted odds ratio (OR) was 1.4 (95% confidence interval (CI)=[1.1, 1.7]). Although indoor NO(2) concentration in the ambient air was assessed only in a subset of the children, the prevalence of lower respiratory symptoms and surrogate exposure variables were available in all of the children at the time of the indoor monitoring program. This paper evaluates the effect of indoor NO(2) exposure on the annual risk of lower respiratory symptoms by applying a regression calibration method to the 2,891 children in the overall study with complete covariate and outcome data, 1,137 of whom had NO(2) directly measured and 1,754 of whom only surrogate exposure data were available. An estimate of the indoor annual NO(2) exposure effect (p.p.b.) is obtained, which is adjusted for measurement error induced by the use of surrogate NO(2) sources among the 1,754. These sources include the presence of a gas stove with or without a pilot light, the presence of a kerosene space heater, the presence of a wood stove, and the usage of a stove for heating, and residential characteristics, including fan usage for kitchen ventilation and the total number of rooms in the home. After adjusting for age, gender, city, parental history of respiratory diseases, and smoking inside the children's home (packs/day), a 15-p.p.b. increment in NO(2) exposure was found to be associated with a significant 50% increased annual risk of lower respiratory symptoms (OR=1.5, 95% CI=[1.2, 1.8]). Simulation results indicated that, under conditions similar to those observed in these data, the estimator is unbiased and has a coverage probability close to the nominal value. Using the methodology illustrated in this paper, it became possible to utilize all data available and obtain a 34% more precise estimate of the NO(2) exposure effect on lower respiratory symptoms, which was adjusted for measurement error due to using NO(2) surrogates instead of directly measured NO(2).

Air Pollution, Indoor↗
PubMed1993

[Psychopharmaceuticals in primary care: prescription quality].

OBJECTIVE: Using criteria based on the bibliography, to assess drugs prescription in a Health Centre, in order to put forward corrective measures in line with the defects identified. DESIGN: Descriptive and retrospective study. SETTING: Santa Maria de Benquerancia Health Centre (Toledo). PARTICIPANTS: A sample of 40% of the clinical records of patients over 14 produced records of patients treated with drugs for psychic disorders between October 1990 and October 1991. MEASUREMENTS AND MAIN RESULTS: 248 prescriptions for these drugs were found. The most common diagnoses were: neurotic depression (33.1%), anxiety (25.8%) and insomnia (10.1%). Benzodiazepines made up 78.2% of the prescriptions. Of 8 quality criteria assessed, the compliance level was acceptable by WHO standards except in the recording in the notes of the diagnosis or problem for which the drug was prescribed (74.2% non-compliance); Alprazolam and Triazolam were not considered first-choice benzodiazepines (31.3% non-compliance); and there was 44.5% non-compliance by Primary Care physicians with the non-prescription of anti-psychotic or stimulant MAO inhibitor antidepressants. CONCLUSIONS: Quality-control studies, such as this one, in order to identify problems, to take corrective measures and subsequently assess them, are useful in improving care procedures.

Drug Prescriptions↗