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Biomedical subjects

J G Wright

Publications and source records attributed to J G Wright.

At least 37 records · Page 2Linked to original sources
PubMed2001

Determining the need for hip and knee arthroplasty: the role of clinical severity and patients' preferences.

BACKGROUND: Area variation in the use of surgical interventions such as arthroplasty is viewed as concerning and inappropriate. OBJECTIVES: To determine whether area arthroplasty rates reflect patient-related demand factors, we estimated the need for and the willingness to undergo arthroplasty in a high- and a low-use area of Ontario, Canada. RESEARCH DESIGN: Population-based mail and telephone survey. SUBJECTS: All adults aged > or =55 years in a high (n = 21,925) and low (n = 26,293) arthroplasty use area. MEASURES: We determined arthritis severity and comorbidity with questionnaires, established the presence of arthritis with examination and radiographs, and evaluated willingness to have arthroplasty with interviews. Potential arthroplasty need was defined as severe arthritis, no absolute contraindication for surgery, and evidence of arthritis on examination and radiographs. Estimates of need were then adjusted for patients' willingness to undergo arthroplasty. RESULTS: Response rates were 72.0% for questionnaires and interviews. The potential need for arthroplasty was 36.3/1,000 respondents in the high-rate area compared with 28.5/1,000 in the low-rate area (P <0.0001). Among individuals with potential need, only 14.9% in the high-rate area and 8.5% in the low-rate area were definitely willing to undergo arthroplasty (P = 0.03), yielding adjusted estimates of need of 5.4/1,000 and 2.4/1,000 in the high- and low-rate areas, respectively. CONCLUSIONS: Demonstrable need and willingness were greater in the high-rate area, suggesting these factors explain in part the observed geographic rate variations for this procedure. Among those with severe arthritis, no more than 15% were definitely willing to undergo arthroplasty, emphasizing the importance of considering both patients' preferences and surgical indications when evaluating need and appropriateness of rates for surgery.

Activities of Daily Living↗
PubMed2001

Short stature as a screening test for endocrinopathy in slipped capital femoral epiphysis.

Slipped capital femoral epiphysis may be associated with hypothyroidism and other endocrinopathies. Routine screening for such abnormalities is unlikely to be cost-effective since the overall incidence of these disorders, in association with slipped capital femoral epiphysis, is low. The identification of a presenting characteristic which would predict the chance of an associated endocrinopathy would allow only selected children to be screened. Our aim was to determine if certain characteristics were useful as a screen for patients with an underlying endocrinopathy who presented with slipped capital femoral epiphysis. Between January 1988 and December 1996 we recorded gender, age, height, unilateral or bilateral involvement and an associated diagnosis of endocrinopathy for all patients who were treated for slipped capital femoral epiphysis. Of 166 such patients 13 (7.8%) had an endocrinopathy. Height was the only useful screening characteristic, although bilateral involvement was more likely in those with an endocrinopathy. Most (90.9%) of this latter group were below the tenth percentile for height compared with only 5.4% in those who did not have an endocrinopathy (p < 0.005). The sensitivity and negative predictive value of detecting an underlying endocrinopathy in a patient presenting with a slipped capital femoral epiphysis and short stature (tenth percentile or less) were 90.2% and 98.6%, respectively. Patients who are on or below the tenth percentile for height at the time of presentation should be screened for a possible endocrine abnormality using measurement of thyroid-stimulating hormone and free thyroxine as a preliminary screening test. These hormones are most likely to be abnormal in the presence of endocrine dysfunction.

Adolescent↗
PubMed2001

All half-lives are wrong, but some half-lives are useful.

The half-life of a drug, which expresses a change in concentration in units of time, is perhaps the most easily understood pharmacokinetic parameter and provides a succinct description of many concentration-time profiles. The calculation of a half-life implies a linear, first-order, time-invariant process. No drug perfectly obeys such assumptions, although in practise this is often a valid approximation and provides invaluable quantitative information. Nevertheless, the physiological processes underlying half-life should not be forgotten. The concept of clearance facilitates the interpretation of factors affecting drug elimination, such as enzyme inhibition or renal impairment. Relating clearance to the observed concentration-time profile is not as naturally intuitive as is the case with half-life. As such, these 2 approaches to parameterising a linear pharmacokinetic model should be viewed as complementary rather than alternatives. The interpretation of pharmacokinetic parameters when there are multiple disposition phases is more challenging. Indeed, in any pharmacokinetic model, the half-lives are only one component of the parameters required to specify the concentration-time profile. Furthermore, pharmacokinetic parameters are of little use without a dose history. Other factors influencing the relevance of each disposition phase to clinical end-points must also be considered. In summarising the pharmacokinetics of a drug, statistical aspects of the estimation of a half-life are often overlooked. Half-lives are rarely reported with confidence intervals or measures of variability in the population, and some approaches to this problem are suggested. Half-life is an important summary statistic in pharmacokinetics, but care must be taken to employ it appropriately in the context of dose history and clinically relevant pharmacodynamic end-points.

Algorithms↗
PubMed2001

Looking for important change/differences in studies of responsiveness. OMERACT MCID Working Group. Outcome Measures in Rheumatology. Minimal Clinically Important Difference.

The purpose of this paper is to describe a classification system for studies of responsiveness that was designed to help organize these studies, and identify those with the potential to provide information on minimal clinically important difference (MCID). We developed a 3 dimensional cube into which studies of responsiveness can be categorized based on their evaluation of 3 attributes: 1. individual or group setting; 2. which scores are contrasted; and 3. the type of change or difference being assessed. We present and discuss examples of studies that fit into categories in the classification cube. This classification system helps to focus attention on whether the literature is able to provide information on the specific type of change a person is interested in. It reinforces that the ability of an instrument to detect a certain category of discrimination within the cube does not mean it will necessarily be responsive to another category. The cube has been shown here as a means to separate out studies that address important change. These studies can then be examined as the source of information on MCID.

Clinical Trials as Topic↗
PubMed2000

The characteristics of patient satisfaction measures.

Information on patient satisfaction is considered a way of including patients' perspectives in the planning and assessment of services. The study of patient satisfaction is a relatively new field, and despite the surge in popularity and use of satisfaction measures during the past three decades, different issues remain to be explored. This is not meant to dissuade clinicians from using satisfaction measures, but rather to allow them to proceed in a thoughtful way, recognizing what these measures can reasonably show us about patients' perceptions of the care and treatment interventions they receive. The proposed approach to classifying the characteristics of patient satisfaction measures should help to highlight potential reasons for variation in results when satisfaction measures perform differently and will be of value if it increases the specificity with which clinicians select measures to achieve their purposes.

Humans↗
PubMed2000

Outcome after prenatal diagnosis of hypoplastic left-heart syndrome: a case series.

BACKGROUND: Traditionally, after prenatal diagnosis of hypoplastic left-heart syndrome (HLHS) couples have been offered termination of pregnancy or comfort care. Success of postnatal surgical options such as the Norwood procedure have been associated with survival of up to 60%. Whether survival is affected by the congenital anomaly being identified prenatally or postnatally remains uncertain. METHODS: We reviewed all cases of prenatally diagnosed HLHS referred to the Fetal Medicine Unit at Birmingham Women's Hospital over 6 years between 1994 and 1999. FINDINGS: 87 cases of HLHS were referred at a median gestational age (95% CI) of 23 (19-37) weeks. Of these, 53 (61%) chose prenatal karyotyping. The overall frequency of abnormal karyotype was found in seven of 59 cases (12%) and associated structural anomalies in 18 of 87 (21%). After counselling, 38 of 87 couples (44%) chose termination of pregnancy. Of the remaining 49 fetuses, 11 (23%) were not considered for postnatal surgery because of parental choice and they died after compassionate care. Of the 36 babies who had surgery postnatally, 12 survived (33%). We recorded a survival rate of 38% for the stage-1 Norwood procedure in the prenatally diagnosed HLHS in our centre. These data suggest that at the point of prenatal detection, the overall survival rate for fetuses with HLHS is 25% (if terminated pregnancies are excluded). INTERPRETATION: Fetal echocardiography allows early diagnosis of HLHS and gives clinicians the opportunity to triage this group dependent on prenatal findings, including karyotyping and the exclusion of other structural anomalies. These prospective data provide up-to-date information on the basis of which parents can make decisions.

Abortion, Induced↗
PubMed2000

Differences between men and women in the rate of use of hip and knee arthroplasty.

BACKGROUND: Previous studies suggest that, for some conditions, women receive fewer health care interventions than men. We estimated the potential need for arthroplasty and the willingness to undergo the procedure in both men and women and examined whether there were differences between the sexes. METHODS: All 48,218 persons 55 years of age or older in two areas of Ontario, Canada, were surveyed by mail and telephone to identify those with hip or knee problems. In these subjects, we assessed the severity of arthritis and the presence of coexisting conditions by questionnaire, documented arthritis by examination and radiography, and conducted interviews to evaluate the subjects' willingness to undergo arthroplasty. The potential need for arthroplasty was defined by the presence of severe symptoms and disability, the absence of any absolute contraindications to surgery, and clinical and radiographic evidence of arthritis. The estimates of need were then adjusted for the subjects' willingness to undergo arthroplasty. RESULTS: The overall response rates were at least 72 percent for the questionnaires and interviews. As compared with men, women had a higher prevalence of arthritis of the hip or knee (age-adjusted odds ratio, 1.76; P<0.001) and had worse symptoms and greater disability, but women were less likely to have undergone arthroplasty (adjusted odds ratio, 0.78; P<0.001). Despite their equal willingness to have the surgery, fewer women than men had discussed the possibility of arthroplasty with a physician (adjusted odds ratio, 0.63). The numbers of people with a potential need for hip or knee arthroplasty were 44.9 per 1000 among women and 20.8 per 1000 among men. After adjustment for willingness to undergo the procedure, the numbers were 5.3 per 1000 for women and 1.6 per 1000 for men. CONCLUSIONS: There is underuse of arthroplasty for severe arthritis in both sexes, but the degree of underuse is more than three times as great in women as in men.

Aged↗
PubMed2000

Early repolarization: an electrocardiographic predictor of enhanced aerobic fitness.

The presence or absence of early repolarization on the electrocardiogram at rest was correlated with aerobic exercise capacity in healthy volunteers from the Baltimore Longitudinal Study of Aging. Patients with early repolarization had both longer treadmill exercise duration and higher peak oxygen consumption than age-and gender-matched control subjects.

Electrocardiography↗
PubMed2000

Measurement properties of the activities scale for kids.

The Activities Scale for Kids (ASK) is a self-report measure of childhood physical disability, that has excellent reliability (ICC = 0.97). The purpose of this study was to assess further the ASK's measurement properties. ASK questionnaires were completed by 200 children with musculoskeletal limitations (mean age, 10.1 years). Rasch analyses confirmed that all items measured the same construct and supported aggregation of a summary score. Validity of the ASK was demonstrated by a correlation of 0.81 (P<0.0001) with parent-reported Childhood Health Assessment Questionnaire scores; a significant difference in scores according to clinicians' global ratings of disability (P<0.0001), and a correlation of 0.92 (P<0.0001) with clinician-observation. The ASK showed minimal ceiling effects, no floor effects, and changed by 1.73 standard deviation units after clinically important change. The ASK is a valid and responsive outcome measure that permits 5- to 15-year-old children physical functioning in the community to be assessed accurately by mail. The quality of this measure will enable clinical studies to measure outcome not only in a way that is relevant to patients, but also in a way that is sensitive to small amounts of change and is practical and inexpensive.

Activities of Daily Living↗
PubMed2000

Evaluating the outcome of treatment. Shouldn't We be asking patients if they are better?

Increasingly clinicians and investigators are recognizing the need to include patients in the assessment of therapy. Patient-based assessments, such as measures of health status or health-related quality-of-life, require patients to rate themselves on a fixed number of questions. Because patients come to their doctors with unique, different, and individual concerns, the concern is that commonly used scales with a fixed number of questions might be excluding important individual concerns or including issues irrelevant to individual patients. Clinicians usually do not rely on health status questionnaires in routine practice to judge the success of therapy, but ask patients directly if they are better. Despite this fundamental interchange between patients and clinicians, relatively little attention has been directed towards the specification, measurement, and quantification of patients' individual concerns. Patient-specific measures are a particular type of measure which allow patients to state their individual concerns, and weight their relative importance. Because we are often trying to address with treatment the concerns of individual patients, patient-specific outcomes would provide us a standardized method useful in research and clinical practice of asking patients whether they are better.

Clinical Medicine↗
PubMed2000

Balloon angioplasty in infants with aortic obstruction after the modified stage I Norwood procedure.

BACKGROUND: The incidence of coarctation after stage I Norwood procedure varies between 11% and 37%, and it contributes to late death after this operation. We describe the incidence and report the results of percutaneous balloon angioplasty of neoaortic arch obstruction in patients after the modified Norwood procedure for hypoplastic left heart syndrome (HLHS). METHODS: During a period of 5 years, 136 patients (94 male, 42 female) underwent a first stage modified Norwood procedure for HLHS. All 95 survivors (69.8%) underwent cardiac catheterization before the second stage. Neoaortic arch obstruction was diagnosed on documentation of a peak systolic gradient of >10 mm Hg across the arch associated with angiographic evidence of localized narrowing of the aortic lumen. RESULTS: Twenty-one (22.1%) of the 95 survivors were documented to have neoaortic arch obstruction. Seventeen patients underwent percutaneous balloon angioplasty for the relief of the neoaortic arch obstruction. The predilatation peak gradient across the arch was reduced significantly by angioplasty from 28.6 +/- 16.9 mm Hg (range 10 to 73 mm Hg) to 5.3 +/- 5.2 mm Hg (range 0 to 19 mm Hg) (P <.001). A final gradient <10 mm Hg or <70% of the starting gradient was considered a success. CONCLUSION: The absence of serious sequelae after the procedure or need for reintervention, as shown by our study, makes balloon angioplasty an effective technique and the treatment of choice for the relief of recoarctation of the neoaortic arch in patients with staged palliation of HLHS.

Angioplasty, Balloon↗
PubMed2000

The relationship between aerobic exercise capacity and circulating IGF-1 levels in healthy men and women.

OBJECTIVES: To determine whether aerobic capacity is associated independently with insulin-like growth factor-I (IGF-1) levels in healthy community-dwelling men and women. SETTING: The Baltimore Longitudinal Study on Aging (BLSA). DESIGN: A cross-sectional analysis of data from the population-based cohort of the Baltimore Longitudinal Study of Aging (BLSA). PARTICIPANTS: We studied 181 men and 92 women aged 20 to 93 years, volunteers in the Baltimore Longitudinal Study on Aging (BLSA). Subjects were free of endocrine, renal, hepatic, gastrointestinal, or cardiac diseases, and they were taking no medications known to interfere with the growth hormone-IGF-1 axis. MEASUREMENTS: All subjects underwent a single measurement of serum IGF-1 in the fasting state, as well as peak VO2 determinations during maximal treadmill exercise testing performed within one visit of the IGF-1 determination. Dual energy X-ray absorptiometry (DEXA) scans were performed in a subset of 171 subjects (64 women and 107 men) for determination of fat free mass (FFM). RESULTS: In the pooled group of women and men, univariate regression analysis revealed that age was correlated strongly with decreasing IGF-1 levels (r = -0.53, P < .001) and with peak VO2r = -0.56, P < .001). IGF-1 levels were also significantly correlated with peak VO2 (r = 0.29, P < .001). There were no significant gender-related differences in these relationships. On multivariate analysis, age (beta = -0.54, P < .001), but not peak VO2 (P = -0.01, P = .840), remained strongly associated with IGF-1 levels. After adjustment of peak VO2 for FFM in subjects with DEXA scans, results were similar. CONCLUSIONS: These findings indicate that although both peak aerobic capacity and circulating IGF-1 levels decline with age, aerobic capacity is not independently related to circulating IGF-1 in healthy men and women across the adult life span.

Absorptiometry, Photon↗
PubMed2000

The reliability and validity of the self-reported patient-specific index for total hip arthroplasty.

BACKGROUND: The Patient-Specific Index is unique in that it reflects how individual patients weigh concerns in rating the outcome of total hip arthroplasty. The Patient-Specific Index was originally administered by an interviewer, which is not always feasible and can be costly. The purposes of the present study were (1) to create a self-reported version of the Patient-Specific Index, (2) to determine the reliability of this new self-reported version, and (3) to determine the relationship between the scores on the new self-reported version and those on the original interviewer-administered version. METHODS: A self-reported version of the Patient-Specific Index was developed, and a pilot test was performed on ten patients. Patients who were scheduled for a total hip arthroplasty or who had recently had a total hip arthroplasty were eligible for the reliability and validity testing. A copy of the new self-reported Patient-Specific Index was mailed to the patients, and they completed it independently. The patients' ratings of the importance and severity of twenty-four concerns prior to total hip arthroplasty were added together to create a summary Patient-Specific Index score. To determine test-retest reliability, patients completed the self-reported Patient-Specific Index a second time, two weeks later. To determine criterion validity, participants also completed the interviewer-administered Patient-Specific Index. RESULTS: Fifty-five patients completed the study. The random-effects intraclass correlation test-retest coefficient was 0.79 (greater than 0.75 represents excellent reliability). The mean Patient-Specific Index scores on the self-reported version and on the interviewer-administered version were 173 and 165 points, respectively (Student t test, p = 0.45). The self-reported Patient-Specific Index was concordant with the interviewer-administered Patient-Specific Index (intraclass correlation coefficient, 0.78). CONCLUSIONS: We concluded that a self-reported version of the Patient-Specific Index, which focuses on the concerns of individuals, is reliable and has criterion validity compared with an interviewer-administered version.

Activities of Daily Living↗
PubMed2000

The treatment of femoral shaft fractures in children: a systematic overview and critical appraisal of the literature.

OBJECTIVE: Through a critical systematic overview of the literature on the treatment of pediatric femoral shaft fractures to determine if any method of treatment can be recommended over others. DATA SOURCES: A MEDLINE search was performed for all cohort and randomized clinical trials for the years 1966 to 1996. STUDY SELECTION: Of 1217 identified articles, 15 cohort studies (where 2 or more treatments were compared in the same study) reported the treatment of children with femoral fractures. DATA EXTRACTION: Information was abstracted and articles rated for quality blind to author, institution and journal. DATA SYNTHESIS: Children having early application of a hip spica cast had an average hospital stay of 11 days (range from 5 to 29 days), average charges of $5784 (range from $590 to $11,800), average rates of limb-length discrepancy (greater than 2 cm) of 3% (range from 0 to 25%), angulatory malunion rates (greater than 10 degrees) of 8% (range from 0 to 19%), and rotational malunion rates (greater than 10 degrees) of 13% (range from 0 to 5%). The costs and malunion rates of early application of a hip spica cast were lower than for traction. Internal fixation (including intramedullary nails) had low angulatory malunion rates compared with early application of a hip spica cast but higher over-lengthening rates (greater than 2 cm) of 25% (range from 5% to 100%) and mean rotational malunion rates (greater than 10 degrees) of 25% (range from 11% to 32%). CONCLUSION: Early application of a hip spica cast had lower costs and malunion rates than traction.

Adolescent↗
PubMed2000

Improving patient satisfaction with time spent in an orthopedic outpatient clinic.

OBJECTIVE: To determine if patient satisfaction can be improved by changing patients' expectations of the clinic visit and by decreasing the total time spent in the clinic. DESIGN: A prospective comparative analysis carried out in 4 phases. SETTING: An university-affiliated orthopedic outpatient clinic. PATIENTS: All patients seen in the orthopedic outpatient clinic were eligible. Phase 1 determined the total clinic time required by patient type; phase 2 assessed baseline satisfaction; phase 3 altered patients' expectations; and phase 4 altered patients' expectations and scheduled visits by patient type. INTERVENTION: Patient questionnaires. MAIN OUTCOME MEASURE: Patient satisfaction with time spent in the clinic. RESULTS: Of 708 distributed questionnaires, 622 (88%) were completed (547 totally complete, 75 partially complete). Total time spent in the clinic decreased across phases 2, 3 and 4 (mean 99.2, 94.7 and 85.2 minutes, respectively, but was significantly different only between phases 3 and 4; p = 0.05, Duncan's multiple range test). The percentage of patients who rated their waiting time as "excellent" increased across phases 2, 3 and 4 (14.6%, 18.8% and 31.1%, respectively; p = 0.0004, chi 2 test). CONCLUSION: Patient satisfaction can be improved by altering patient expectations and by decreasing the total time spent in clinic.

Female↗
PubMed1999

Outcomes research in surgery.

The phrase "outcomes studies" is usually used to describe those studies where outcome is assessed in large cohorts of patients, often using data from administrative databases. They are used to determine the role and impact of variations in the structure and process of health care delivery play in routine practice. Optimally, outcome should be assessed in terms of measures that are important to patients (e.g., quality of life). More often, clinically relevant outcome measures are lacking, and outcome is measured in terms of mortality, morbidity, and length of hospital stay. Although the outcomes movement continues to expand and much valuable information can be learned from this type of study, there are limitations. These studies are essentially observational and most often are performed using databases set up for other purposes. Thus data may be incomplete and incorrect. Moreover, they cannot assess the impact of patient preferences on outcome. The term outcomes studies has also been applied to small area variation and volume outcome studies.

Humans↗