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P Ravaud

Publications and source records attributed to P Ravaud.

At least 55 records · Page 3Linked to original sources
PubMed2000

Follow-up of individual patients on two DXA scanners of the same manufacturer.

Measuring and monitoring changes in bone mineral density (BMD) is usually done by dual-energy X-ray absorptiometry (DXA). Replacement of old devices is becoming increasingly frequent. To cross-calibrate two Hologic devices, a QDR 1000 and a QDR 4500A, we measured three phantoms - a Hologic spine phantom, a Hologic block phantom (without and with subregions analysis) and a European Spine Phantom - 20 times each without repositioning on both devices. The mean difference between BMD obtained on the two devices was 0.003, 0.033, 0.051 and -0.045 g/cm2 respectively. We also measured the spine and hip of 60 women aged 19-78 years twice on the same day on both devices. Another group of 30 women aged 52-83 years were measured twice on the QDR 4500 A device (15 days apart). We analyzed the data using Pearson's correlation coefficient, and Bland and Altman's method, and calculated the smallest detectable difference (SDD). Results on the two devices were highly correlated: r2 = 0.99, 0.95, 0.96 for spine, femoral neck and total hip BMD respectively. SDD was higher for scans done on different devices than for those done twice on the same device: the SDDs were 0.048, 0.046 and 0.047 g/cm2 for spine, femoral neck and total hip BMD respectively measured on two different devices, while the equivalent values were 0.034, 0.036 and 0.027 g/cm2 using a single device. The difference in BMD results was not dependent on BMD. Our results suggest that, although devices are properly cross-calibrated, differences among them great enough to be clinically relevant can be observed in vivo.

Absorptiometry, Photon↗
PubMed2000

From clinical recommendations to mandatory practice. The introduction of regulatory practice guidelines in the French healthcare system.

In an effort to control ambulatory care costs, regulatory practice guidelines (références médicales opposables or RMOs) were introduced by law in France in 1993. RMOs are short sentences, negatively formulated ("it is inappropriate to..."), covering medical and surgical topics, diagnosis, and treatment. Since their introduction, physicians who do not comply with RMOs can be fined. The fine is determined by a weighted combination of indices of harm, cost, and the number of violations. The impact of the RMO policy on physician practice has been questioned, but so far few evaluations had been performed. At the end of 1997, only 121 physicians had been fined (0.1% of French private physicians). The difficulty of controlling physicians, the large number of RMOs, and the lack of a relevant information system limit the credibility of this policy. The simultaneous development of a clinical guideline program to improve the quality of care and of a program to control medical practice can lead to a misunderstanding among clinicians and health policy makers. Financial incentives or disincentives could be used to change physician behavior, in addition to other measures such as education and organizational changes, if they are simple, well explained, and do not raise any ethical conflict. But these measures are dependent on the structure and financing of the healthcare system and on the socioeconomic and cultural context. More research is needed to assess the impact of interventions using financial incentives and disincentives on physician behavior.

France↗
PubMed2000

Radiographic assessment of hip osteoarthritis progression: impact of reading procedures for longitudinal studies.

OBJECTIVE: To compare radiographic reading procedures and evaluate their impact on sample size in hip osteoarthritis (OA) longitudinal studies. METHODS: Pelvic radiographs performed twice, three years apart, in 104 patients with hip OA were read by a single reader using the Kellgren and Lawrence system, joint space narrowing scale, and joint space width (JSW). Reading procedures were (a) films read as single radiographs, (b) films grouped by patient but read in random order, (c) films grouped by patient and chronologically ordered, all with landmarks for JSW measurements, (d) films read as single radiographs, without landmarks for JSW measurements. JSW was measured at the narrowest point with a 0.1 mm graduated magnifying glass. RESULTS: More Kellgren and Lawrence or joint space narrowing grades were modified respectively with the single (42% and 37%) than with the paired (32% and 23%) or chronologically ordered (34% and 29%) reading procedures. Variability of JSW progression was principally related to mean progression (88.3%) and landmarks (almost 10%). Standardised response means were -0.71 with the paired reading procedure with landmarks, -0.68 with the single reading procedure with landmarks, -0.65 with the single reading procedure without landmarks. With landmarks, 10% more patients would be needed using single than paired reading. Using single reading, 10% more patients would be needed without landmarks than with landmarks. CONCLUSION: Kellgren and Lawrence grading seems to be influenced by the reading procedure, as is joint space narrowing grading, for assessing hip OA. Paired reading procedure with landmarks for JSW should be recommended in longitudinal studies.

Disease Progression↗
PubMed2000

[Evaluation of clinical decision rules].

The final goal of decision making rules is to help the clinician make a medical decision and limit heterogeneous practices. Three steps are needed to develop decision making rules for use in daily practice: 1) construction, 2) prospective validation, 3) study of its impact in terms of clinical practice and economics. The aim of this work was to review the details of these different steps basing the research on the Ottawa rules aimed at defining indications for radiography in patients presenting at the emergency room for ankle trauma.

Adolescent↗
PubMed1999

[Are mortality indicators acceptable indicators for the quality of health care?].

IMPORTANCE OF PUBLISHING MORTALITY RATES: Mortality rates for certain interventions or disease states have been used over the last decade as indicators of the quality of care provided by a given hospital, unit or, medical team. If published, these rates would be a useful tool for decision makers in the process of fund allocations, for public information, and for promoting improved care in hospitals or units with a low classification. METHODOLOGICAL LIMITATIONS: It is difficult to adjust an indicator of mortality to disease-related risk factors and any modification of this adjustment can have major consequences on the validity of subsequent comparisons. The differences in mortality observed between hospitals and physicians can reflect not only differences in quality of care but also differences in approaches to disease-related risk factors, therapeutic choices, or coding practices. The lack of statistical power is a major limiting factor in interpreting differences in mortality rates. To evidence a statistically significant difference in mortality between two hospitals whose rates are respectively 0.5% and 1% (for example in total hip replacement patients), it would be necessary to include 4673 patients, a number which would correspond to 20 years data for a hospital performing 230 interventions per year. Consequently, the number of interventions performed in the most active hospitals would not be sufficient to make such comparisons. LIMITATIONS AND COUNTER EFFECTS: Some studies have demonstrated that the publication of mortality rates does not have a major influence on patients' decisions nor on physicians' choice of a referral hospital. It would have no effect on improving health care quality of the institutions cited. One the contrary, certain counter effects have been observed: modification in patient recruitment, higher-risk patients being referred to hospitals with unpublished mortality rates. For many authors, procedure indicators are more pertinent than outcome indicators for detecting differences in health care quality between different care structures.

France↗
PubMed1999

[Does continuing medical education improve the way physicians conduct their practice?].

OBJECTIVES: Physicians practicing in France are required to participate in continuing education programs in accordance with the code of deontology and the official decree on controlling medical expenditures. We reviewed the literature to analyze the efficacy of such training on the way physicians conduct their practice. METHODS: We examined the following educational methodologies: diffusion of educational documents or guidelines, conferences and presentations, interventions by opinion leaders, direct visits at the physician's office. The analysis was based solely on publications issuing from work considered to be valid in accordance with the Cochrane collaboration: intervention trials, chronological series, before-after studies with control group. RESULTS: The diffusion of educational material or more formal continuing education programs do not appear to have an effect on the way physicians conduct their practice. Interventions by opinion leaders have a demonstrated impact but are rarely judged clinically significant. Visits to the physician's office by specially trained health care workers have an effect but this mode of education is costly. CONCLUSIONS: The conventional strategies, such as simple information diffusion and continuing education programs, developed to promote an evolution of clinical practices appear to be the least effective methodologies.

Education, Medical, Continuing↗
PubMed1999

Effects of joint lavage and steroid injection in patients with osteoarthritis of the knee: results of a multicenter, randomized, controlled trial.

OBJECTIVE: To evaluate the efficacy of joint lavage and intraarticular steroid injection, alone and in combination, in the treatment of patients with symptomatic knee osteoarthritis (OA). METHODS: Ninety-eight patients with painful tibiofemoral OA were enrolled in a prospective, randomized, controlled, 2 x 2 factorial-design trial of 6 months' duration. The 4 treatment groups consisted of 1) intraarticular placebo (1.5 ml of 0.9% normal saline), 2) intraarticular corticosteroids (3.75 mg of cortivazol in 1.5 ml), 3) joint lavage and intraarticular placebo, and 4) joint lavage and intraarticular corticosteroid. Outcome measures evaluated at baseline, week 1, week 4, week 12, and week 24 included severity of pain (100-mm visual analog scale [VAS]), global status (100-mm VAS), and Lequesne's functional index. RESULTS: No interaction between steroid injection and joint lavage was demonstrated. Patients who had undergone joint lavage had significantly improved pain VAS scores at week 24 (P = 0.020). In contrast, corticosteroid injection had no long-term effect (P = 0.313); corticosteroid injection was associated with a decrease in pain only at week 1 (P = 0.003) and week 4 (P = 0.020). After week 4, Lequesne's functional index was not significantly improved regardless of the assigned treatment. CONCLUSION: Compared with placebo, both treatments significantly relieved pain but did not improve functional impairment. The effects of the 2 treatments were additive. Cortivazol provided short-term relief of pain (up to week 4). The effects of joint lavage persisted up to week 24.

Aged↗
PubMed1999

Accuracy and precision of 62 bone densitometers using a European Spine Phantom.

Dual-energy absorptiometry (DXA) is widely used for bone mineral density measurements. Different types of devices are available. Differences between devices from either the same manufacturer or different manufacturers can lead to difficulties in clinical practice when patients are followed on different machines. We calculated the accuracy and precision of 62 DXA devices from two manufacturers (51 Hologic, 11 Lunar) using a European Spine Phantom (ESP, semi-anthropomorphic). The ESP was measured 5 times on each device without repositioning. Accuracy was assessed by comparing bone mineral density (BMD, g/cm(2)) values measured on each device with the actual value of the phantom. Precision was assessed by the coefficient of variation (CVsd), using the root mean square average. The limits of agreement were estimated from the differences between each replicate measurement of BMD and the estimated true value for a particular manufacturer, according to Bland and Altman. The results confirm the difference between devices from different manufacturers (18.5%). Mean CVsd values were 0.57% and 0.64% for Hologic and Lunar respectively. The limits of agreement among devices from the same manufacturer were 0.026 g/cm(2) and 0.025 g/cm(2) for Hologic and Lunar respectively. Differences in extreme results between devices from the same manufacturer were on average 5.4% and 3.6% for Hologic and Lunar respectively. Results of different devices from the same manufacturer are highly comparable, although unpredictable differences exist that may be clinically relevant.

Absorptiometry, Photon↗
PubMed1999

Assessing smallest detectable change over time in continuous structural outcome measures: application to radiological change in knee osteoarthritis.

Interpreting changes in continuous structural outcome measures is a common problem in clinical research and in daily practice. We propose a method for estimating whether difference observed between two successive measures in an individual constitutes a statistically relevant change or a change induced by variability. This statistically relevant change is based on an analysis of reproducibility. The continuous structural outcome measure investigated as an example was joint space width (JSW) measurement on standard X-rays, which is known to be the primary end-point for assessing structural osteoarthritis progression. The results of the present study demonstrate that cutoffs are closely dependent on all sources of variabilities in JSW measurement such as joint positioning, radiographic procedure, and the measurement process itself. Therefore, we suggest to determine cutoffs for each study using a representative sample of the population studied and using the procedures and methods of measurement of the specific study. This approach may easily be extended to other continuous structural outcome measures.

Aged↗
PubMed1999

Construction of a scale measuring inpatients' opinion on quality of care.

OBJECTIVE: To develop a reliable and valid measure of patient opinions on quality of hospital care. DESIGN: Issues of importance to patients and possible scale items were generated by literature review and non-structured interviews of patients, former patients, health care providers and researchers. Semi-structured interviews with inpatients and pilot studies were conducted to modify or remove ambiguous questions and reduce skewed responses. A study was then made to select from these questions relevant items and variables correlated to patient evaluation of quality of care. A principal-components analysis was performed to select items and assess construct validity. Cronbach's alpha coefficients were calculated to estimate the reliability of the scale. Time reliability and concurrent validity were also considered. SETTING: An 800-bed French short-stay teaching hospital in Paris. STUDY PARTICIPANTS: Five-hundred and thirty-four consecutive patients hospitalized in eight medical and surgical wards. RESULTS: A 26-item scale was developed. Component analysis indicated two subscales: 'medical information' and 'relationship with staff and daily routine'. Levels of reliability were satisfactory: Cronbach's alpha coefficient exceeded 0.87 for overall scale and subscales. Concurrent validity and time reliability were also satisfactory. Multivariate analysis showed that, taking into account patients and hospitalization characteristics linked to scores (age, health status, number of hospitalizations, comorbidity, time since diagnosis, admission pattern, private patient and difficulties reported by staff), these scores differed among departments. CONCLUSION: A reliable, valid measure of inpatients' opinions on quality of care has been developed in a French hospital and variables that have to be taken into account to compare hospital departments have been selected. Items selected in the scale emphasized the importance that patients give to receiving medical information.

Aged↗
PubMed1999

Are radiological joint space widths of normal hips asymmetrical?

BACKGROUND: To be certain that the joint space width is abnormal in the case of hip joint pain when compared with the contralateral hip requires knowledge of physiological dissymmetry. AIM OF THE STUDY: To assess interindividual variability and dissymmetry in pelvic radiological joint space width. METHODS: Pelvic radiographs of subjects without hip joint disease. Measurement with a 0.1 mm graduated magnifying glass and 0.5 mm graduated flat ruler at the hip superointermediate site (vertical going through the femoral head centre). After randomisation of the side to measure, analysis of nine groups of 19 plain films by one investigator blind for the result of the contralateral side. RESULTS: The difference between the left and right hip was plotted against the corresponding mean for all 171 normal subjects. This shows the frequency and the limits of the asymmetry at each measurement site. The asymmetry is independent of interindividual variability of the joint space width and greater than the measurement error in most subjects. CONCLUSION: This study confirms the interindividual variability of hip joint space width, shows the frequency of hip joint space asymmetry and defines its limit.

Female↗
PubMed1999

Individual smallest detectable difference in bone mineral density measurements.

Bone mineral density (BMD) measurement is a major outcome measure in osteoporosis. The BMD changes observed must exceed the variability inherent in the measurement process to be considered related to disease progression. The objective of the study was to estimate short-term variability of BMD measurement and to propose a cut-off value for the smallest detectable BMD changes for an individual. To estimate the short-term variability, 70 healthy postmenopausal women aged 53 +/- 4 years (group 1) and 57 elderly osteoporotic postmenopausal women aged 80 +/- 6 years (group 2) had two repeated BMD measurements of the lumbar spine (L2-L4) and the proximal femur with dual-energy X-ray absorptiometry, with complete repositioning within 1 h. Cut-offs derived from short-term variability were either estimated from the coefficient of variation (CV) (which is a function of the measured value) or from the standard deviation (SD), and applied to 330 postmenopausal women (group 3) who had BMD measurements at baseline and 2 years later. The short-term intrasubject variability was greater at the lumbar spine in group 2 versus group 1 (0.0123 vs. 0.0059 g/cm2, p < 10-4), whereas it was not at the femoral neck (0.0098 vs. 0.0076 g/cm2, p = 0.28). There was no statistically significant correlation between short-term intrasubject variability (SD) and BMD as demonstrated with an analysis of covariance (p values ranging from 0.17 to 0.90). Cut-offs estimated with SD and CV were individually applied to group 3 patients. Using these two cut-offs, discrepancies in assessment of progression were observed in 1.7-8.6% of cases. Short-term BMD variability is constant in a wide range of BMD values. Consequently, to determine cut-off values for the smallest detectable differences in BMD at the individual level, precision errors should be based on SD (expressed in absolute units) rather than on CV (expressed in percentage).

Absorptiometry, Photon↗