Biomedical subjects

N Laird

Publications and source records attributed to N Laird.

15 recordsLinked to original sources

PubMed1995

Incidence of adverse drug events and potential adverse drug events. Implications for prevention. ADE Prevention Study Group.

OBJECTIVES: To assess incidence and preventability of adverse drug events (ADEs) and potential ADEs. To analyze preventable events to develop prevention strategies. DESIGN: Prospective cohort study. PARTICIPANTS: All 4031 adult admissions to a stratified random sample of 11 medical and surgical units in two tertiary care hospitals over a 6-month period. Units included two medical and three surgical intensive care units and four medical and two surgical general care units. MAIN OUTCOME MEASURES: Adverse drug events and potential ADEs. METHODS: Incidents were detected by stimulated self-report by nurses and pharmacists and by daily review of all charts by nurse investigators. Incidents were subsequently classified by two independent reviewers as to whether they represented ADEs or potential ADEs and as to severity and preventability. RESULTS: Over 6 months, 247 ADEs and 194 potential ADEs were identified. Extrapolated event rates were 6.5 ADEs and 5.5 potential ADEs per 100 nonobstetrical admissions, for mean numbers per hospital per year of approximately 1900 ADEs and 1600 potential ADEs. Of all ADEs, 1% were fatal (none preventable), 12% life-threatening, 30% serious, and 57% significant. Twenty-eight percent were judged preventable. Of the life-threatening and serious ADEs, 42% were preventable, compared with 18% of significant ADEs. Errors resulting in preventable ADEs occurred most often at the stages of ordering (56%) and administration (34%); transcription (6%) and dispensing errors (4%) were less common. Errors were much more likely to be intercepted if the error occurred earlier in the process: 48% at the ordering stage vs 0% at the administration stage. CONCLUSION: Adverse drug events were common and often preventable; serious ADEs were more likely to be preventable. Most resulted from errors at the ordering stage, but many also occurred at the administration stage. Prevention strategies should target both stages of the drug delivery process.

Boston↗

PubMed1995

Systems analysis of adverse drug events. ADE Prevention Study Group.

OBJECTIVE: To identify and evaluate the systems failures that underlie errors causing adverse drug events (ADEs) and potential ADEs. DESIGN: Systems analysis of events from a prospective cohort study. PARTICIPANTS: All admissions to 11 medical and surgical units in two tertiary care hospitals over a 6-month period. MAIN OUTCOME MEASURES: Errors, proximal causes, and systems failures. METHODS: Errors were detected by interviews of those involved. Errors were classified according to proximal cause and underlying systems failure by multidisciplinary teams of physicians, nurses, pharmacists, and systems analysts. RESULTS: During this period, 334 errors were detected as the causes of 264 preventable ADEs and potential ADEs. Sixteen major systems failures were identified as the underlying causes of the errors. The most common systems failure was in the dissemination of drug knowledge, particularly to physicians, accounting for 29% of the 334 errors. Inadequate availability of patient information, such as the results of laboratory tests, was associated with 18% of errors. Seven systems failures accounted for 78% of the errors; all could be improved by better information systems. CONCLUSIONS: Hospital personnel willingly participated in the detection and investigation of drug use errors and were able to identify underlying systems failures. The most common defects were in systems to disseminate knowledge about drugs and to make drug and patient information readily accessible at the time it is needed. Systems changes to improve dissemination and display of drug and patient data should make errors in the use of drugs less likely.

Boston↗

PubMed1995

Age, period, and cohort effects on pulmonary function in a 24-year longitudinal study.

This paper proposes the use of two-factor models (age-period and age-cohort models) to estimate age, period, and cohort effects on pulmonary function by using the data collected in a 24-year longitudinal study in the Netherlands from 1965 to 1990. The analysis included 18,363 pulmonary function measurements on 6,148 subjects aged 20-54 years at the initial visit. The subjects were grouped into four birth cohorts (before 1923, 1923-1934, 1935-1946, and after 1946) and four survey periods (1965-1972, 1973-1978, 1979-1984, and 1985-1990). In the age-cohort model, the decrement in forced expiratory volume in 1 second (FEV1) associated with a yearly increase in age was 28.3 +/- 3.7 ml/year for a man 176 cm tall and 16.0 +/- 1.9 ml/year for a woman 163 cm tall. The estimated acceleration of decline with aging was significant for both men (beta = -0.212; standard error = 0.079 ml) and women (beta = -0.346; standard error = 0.058 ml). Compared with that of the cohort born before 1923, the average level of FEV1 was estimated to increase by 156, 277, and 379 ml, respectively, for the three younger cohorts in men (p = 0.01) and by 133, 213, and 328 ml for the three younger cohorts in women (p < 0.01). In the age-period model, the estimated linear age effect on FEV1 was 36.2 +/- 4.2 ml/year for a man and 30.5 +/- 2.3 ml/year for a woman. The age quadratic term was significant for women, but not for men. Average FEV1 was estimated to be increased by 141, 169, and 250 ml, respectively, for the periods 1973-1978, 1979-1984, and 1985-1990 in men and by 131, 138, and 219 ml in women. These period effects were significant for both men and women. In summary, this study applied the two-factor models to estimate cross-sectional and longitudinal effects of aging on FEV1 and demonstrated significant period and cohort effects, which could be attributed in part to changes in air pollutants, respiratory infections, vaccinations, types of cigarettes, diet, and lifestyles over time.

Age Factors↗

PubMed1991

The nature of adverse events in hospitalized patients. Results of the Harvard Medical Practice Study II.

BACKGROUND: In a sample of 30,195 randomly selected hospital records, we identified 1133 patients (3.7 percent) with disabling injuries caused by medical treatment. We report here an analysis of these adverse events and their relation to error, negligence, and disability. METHODS: Two physician-reviewers independently identified the adverse events and evaluated them with respect to negligence, errors in management, and extent of disability. One of the authors classified each event according to type of injury. We tested the significance of differences in rates of negligence and disability among categories with at least 30 adverse events. RESULTS: Drug complications were the most common type of adverse event (19 percent), followed by wound infections (14 percent) and technical complications (13 percent). Nearly half the adverse events (48 percent) were associated with an operation. Adverse events during surgery were less likely to be caused by negligence (17 percent) than nonsurgical ones (37 percent). The proportion of adverse events due to negligence was highest for diagnostic mishaps (75 percent), noninvasive therapeutic mishaps ("errors of omission") (77 percent), and events occurring in the emergency room (70 percent). Errors in management were identified for 58 percent of the adverse events, among which nearly half were attributed to negligence. CONCLUSIONS: Although the prevention of many adverse events must await improvements in medical knowledge, the high proportion that are due to management errors suggests that many others are potentially preventable now. Reducing the incidence of these events will require identifying their causes and developing methods to prevent error or reduce its effects.

Adolescent↗

PubMed1989

Meta-analytic evidence against prophylactic use of lidocaine in acute myocardial infarction.

Although lidocaine prophylaxis reduces the incidence of ventricular fibrillation during acute myocardial infarction (AMI), randomized control trials (RCTs) have not demonstrated any significant mortality effect of this therapy. We conducted a meta-analysis of 14 RCTs of lidocaine prophylaxis during AMI to detect any mortality effect. Six prehospital- and eight hospital-phase RCTs that randomized totals of 7656 and 1407 patients, respectively, were selected and reviewed in a blinded fashion. Mortality data were evaluated according to therapy type, reporting interval, and patient category. The prehospital-phase RCTs showed no meaningful mortality effect (risk difference, 0.0184; 95% confidence interval, -0.048 to +0.012). The hospital-phase RCTs showed a statistically significant increase in mortality during the treatment period for lidocaine recipients (risk difference, 0.029; 95% confidence interval, +0.004 to +0.055). These results confirm that lidocaine administered to monitored patients during the prehospital phase of AMI will not reduce mortality by a clinically important amount and suggest that lidocaine administered in the hospital phase of monitored, uncomplicated AMI may increase mortality among recipients with proved AMI.

Clinical Trials as Topic↗

PubMed1986

Meta-analysis in clinical trials.

This paper examines eight published reviews each reporting results from several related trials. Each review pools the results from the relevant trials in order to evaluate the efficacy of a certain treatment for a specified medical condition. These reviews lack consistent assessment of homogeneity of treatment effect before pooling. We discuss a random effects approach to combining evidence from a series of experiments comparing two treatments. This approach incorporates the heterogeneity of effects in the analysis of the overall treatment efficacy. The model can be extended to include relevant covariates which would reduce the heterogeneity and allow for more specific therapeutic recommendations. We suggest a simple noniterative procedure for characterizing the distribution of treatment effects in a series of studies.

Clinical Trials as Topic↗

PubMed1984

Cutaneous squamous-cell carcinoma in patients treated with PUVA.

A 5.7-year prospective study of 1380 patients treated for psoriasis with oral methoxsalen (8-methoxypsoralen) and ultraviolet A photochemotherapy (PUVA) revealed that after adjustment for exposures to ionizing radiation and topical tar preparations, the risk that cutaneous squamous-cell carcinoma would develop at least 22 months after the first exposure to PUVA was 12.8 times higher in patients exposed to a high dose than in those exposed to a low dose (95 per cent confidence interval, 5.8 to 28.5). No substantial dose-related increase was noted for basal-cell carcinoma. The dose-dependent risk of cutaneous squamous-cell carcinoma suggests that PUVA can act as an independent carcinogen. In our study, morbidity associated with these tumors has been limited, but further follow-up is needed. Meanwhile, patients treated with PUVA should be followed closely for the possible development of cutaneous squamous-cell carcinoma.

Adult↗

PubMed1984

The effects of the WIC program on the growth of infants.

The Special Supplemental Food Program for Women, Infants and Children (WIC) provides food supplements and nutrition counseling to pregnant and lactating women and children up to age 5 who are at nutritional risk. The purpose of this study was to determine the effects of the program on the growth of infants. Retrospective longitudinal anthropometric data were obtained on 906 WIC and 1001 non-WIC infants from birth to 18 months of age. A new methodology was developed that addressed two factors in longitudinal studies frequently confounded with program impact: 1) regression to the mean and 2) expected growth. Regression analyses indicated that children who were on WIC between 6 and 18 months of age were growing at greater than expected rates. The most persistent program effect was at 6 months of age, after the children had been on the program for an average of 4 months. The study indicated that data routinely collected by the program can be used for evaluation purposes.

Body Weight↗

PubMed1984

Random-effects models for serial observations with binary response.

This paper presents a general mixed model for the analysis of serial dichotomous responses provided by a panel of study participants. Each subject's serial responses are assumed to arise from a logistic model, but with regression coefficients that vary between subjects. The logistic regression parameters are assumed to be normally distributed in the population. Inference is based upon maximum likelihood estimation of fixed effects and variance components, and empirical Bayes estimation of random effects. Exact solutions are analytically and computationally infeasible, but an approximation based on the mode of the posterior distribution of the random parameters is proposed, and is implemented by means of the EM algorithm. This approximate method is compared with a simpler two-step method proposed by Korn and Whittemore (1979, Biometrics 35, 795-804), using data from a panel study of asthmatics originally described in that paper. One advantage of the estimation strategy described here is the ability to use all of the data, including that from subjects with insufficient data to permit fitting of a separate logistic regression model, as required by the Korn and Whittemore method. However, the new method is computationally intensive.

Air Pollution↗

PubMed1983

Viral and epidemiologic studies of idiopathic sudden hearing loss.

The relationship between viral seroconversions and idiopathic sudden hearing loss (ISHL) is studied. Compared with our control group, the incidence of viral seroconversions is greater among ISHL patients, both for single and multiple viral infections. There was a significantly greater number of patients with seroconversions to mumps, rubeola, varicella-zoster, cytomegalovirus, and influenza B. We were unable to find a relationship between viral seroconversion and type or degree of hearing loss, vertigo, or chance for recovery. The incidences of viral conversion and sudden hearing loss track one another closely, suggesting that viral infection is a major cause of ISHL. During this 3-year study in Boston, ISHL was most prevalent in the spring.

Adolescent↗

PubMed1982

The relationship of idiopathic sudden hearing loss to diabetes mellitus.

A diabetic subgroup identified from a base population who have experienced idiopathic sudden hearing loss (ISHL) has been studied. In order to assess the relationship between diabetes and ISHL, two non-diabetic control groups were formed, and a comparison of the audiological data between the diabetic and non-diabetic ISHL patient was made. Mean degree of hearing loss and recovery, as well as the mean hearing level of the contralateral ear were analyzed. No statistically significant differences were noted in the audiological pattern of ISHL in diabetics and controls. A similar incidence of recovery was noted for the two groups throughout the mid frequencies; however, diabetic ISHL patients fail to recover as well as in the high frequencies. Preliminary data, while not statistically significant, suggest an increased hearing loss in both the affected and unaffected ear of the older diabetic patient.

Adult↗

PubMed1980

The efficacy of steroids in the treatment of idiopathic sudden hearing loss. A double-blind clinical study.

Double-blind studies were conducted for the treatment of idiopathic sudden hearing loss (ISHL) with oral steroids. The condition was defined as not less than a 30-dB loss over three contiguous frequencies in three days or less. Follow-up audiograms were obtained four weeks and three months later. Specific audiologic guidelines for the assessment of hearing recovery were used to ensure objectivity. Steroids had a statistically significant effect on the recovery of hearing in patients with moderate hearing losses. The nature of the hearing loss and its susceptibility to improvement with steroid therapy lend support to the hypothesis that viral cochlitis is the primary cause of ISHL.

Adult↗

PubMedDate not supplied

Electronystagmographic findings in idiopathic sudden hearing loss.

The electronystagmographic findings for 116 patients with unilateral idiopathic sudden hearing loss (ISHL) were analyzed. For the purpose of the study, three groups were formed: patients with normal electronystagmographic (ENG) findings; patients with mild to moderate vestibular injuries consisting of spontaneous horizontal nystagmus or directional preponderance; and patients with severe vestibular injuries indicated by reduced vestibular responses, including paresis of the semicircular canal or lack of response to caloric testing. Clinical and audiologic findings were compared. High correlations were found between both subjective vertigo and abnormal ENG findings and the presence of profound hearing loss at the onset of ISHL. There was an inverse relationship between recovery from ISHL and the ENG findings, namely, as the severity of the vestibular injury increased, the percentage of patients who achieved recovery decreased. Patients with abnormal ENGs had a greater mean hearing loss at onset of ISHL and less mean recovery of hearing than did patients who had normal ENG findings. In addition, patients who had abnormal ENG findings recovered less fully from hearing loss in the high frequencies than from those in the low frequencies owing to the proximity of the basilar turn of the cochlea to the vestibular sense organ.

Adolescent↗

PubMedDate not supplied

Predicting recovery from idiopathic sudden hearing loss.

The probability of recovery from idiopathic sudden hearing loss depends on many factors, including patient age, presence of vertigo, audiogram type at diagnosis, and electronystagmographic test results. The authors present a model for calculating the probability of patient recovery based on the combined effects of risk factors determined for these variables. Data collected from 123 patients with "profound" or "moderate" sudden hearing losses are used to illustrate the model. Interrelationships among the prognostic factors and their relative importances in predicting hearing recovery are discussed.

Adolescent↗

PubMedDate not supplied

Efficacy of an H1 antagonist, astemizole, for chronic allergic rhinitis.

Astemizole, a new histamine H1 receptor antagonist, was tested in a double-blind cross-over comparison study with chlorpheniramine maleate, a very effective conventional H1 antagonist, in patients with chronic allergic rhinitis. Astemizole was found to be equally effective, yet there was a significant decrease in the side effects of sleepiness (P less than .01) and dry mouth (P less than .05). Astemizole has a completely different structure and binding curves from terfenadine. It is approved for clinical use in the United Kingdom, Canada, and many European countries.

Astemizole↗