The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
F Halter - One of the best experts on this subject based on the ideXlab platform.
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wallstents versus plastic stents in malignant biliary obstruction effects of stent patency of the first and second stent on Patient Compliance and survival
The American Journal of Gastroenterology, 1996Co-Authors: A Schmassmann, E Von Gunten, J Knuchel, U Scheurer, H Fehr, F HalterAbstract:Objectives : In prospective trials in Patients with malignant biliary obstruction, it has been reported that Wallstents prolong stent patency, but this does not translate into a significant survival benefit. Compared with prospective trials, however, survival may be different in clinical practice because of differences in Patient Compliance. We report on a retrospective, long term analysis comparing Wallstents versus plastic stents. Methods : Plastic endoprostheses (70 Patients) and endoscopic Wallstents (95 Patients) were placed in 165 consecutive Patients with irresectable, malignant biliary obstruction in a first (1990-91) and second (1992-93) time period. Stent occlusion was treated by plastic stent placement. Results : Patient characteristics were quite comparable in both stent groups. Initial placement of a Wallstent resulted in an increase of median stent patency of the first (10 vs 4 months, p < 0.001) and second (8 vs 3 months, p < 0.05) stent, a decrease of additional endoscopic procedures (20 vs 58%, p < 0.005), an increase of Patient Compliance reflected by a decrease of Patients dying with untreated stent occlusion (9 vs 30%, p < 0.001), and an increase of survival time (6.5 vs 4 months, p < 0.05). Conclusions : Initial placement of a Wallstent results in an increase of stent patency of the first and second stent. Duration of stent patency appears to have a determinant effect on Patient Compliance. Increased stent patency and Patient Compliance seem to improve survival in clinical practice.
Pascal Girard - One of the best experts on this subject based on the ideXlab platform.
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Pharmacokinetically Based Estimation of Patient Compliance with Oral Anticancer Chemotherapies
Clinical Pharmacokinetics, 2009Co-Authors: Emilie Hénin, Véronique Trillet-lenoir, Catherine Rioufol, Brigitte Tranchand, Pascal GirardAbstract:Background and objectives More and more anticancer chemotherapies are now available as oral formulations. This relatively new route of administration in oncology leads to problems with Patient education and non-Compliance. The aim of this study was to explore the performances of the ‘inverse problem’, namely, estimation of Compliance from pharmacokinetics. For this purpose, we developed and evaluated a method to estimate Patient Compliance with an oral chemotherapy in silico (i) from an a priori population pharmacokinetic model; (ii) with limited optimal pharmacokinetic information collected on day 1; and (iii) from a single pharmacokinetic sample collected after multiple doses. Methods Population pharmacokinetic models, including estimation of all fixed and random effects estimated on a prior dataset, and sparse samples taken after the first dose, were combined to provide the individual POSTHOC Bayesian pharmacokinetic parameter estimates. Sampling times on day 1 were chosen according to a D-optimal design. Individual pharmacokinetic profiles were simulated according to various dose-taking scenarios. To characterize Compliance over the n previous dosing times (supposedly known without error), 2^n different Compliance scenarios of doses taken/not taken were considered. The observed concentration value was compared with concentrations predicted from the model and each Compliance scenario. To discriminate between different Compliance profiles, we used the Euclidean distance between the observed pharmacokinetic values and the predicted values simulated without residual errors. This approach was evaluated in silico and applied to imatinib and capecitabine, the pharmacokinetics of which are described in the literature, and which have quite different pharmacokinetic characteristics (imatinib has an elimination half-life of 17 hours, and α-fluoro-β-alanine [FBAL], the metabolite of capecitabine, has an elimination half-life of 3 hours). 1000 parameter sets were drawn according to population distributions, and concentration values were simulated at several timepoints under various Compliance patterns to compare with the predicted ones. In addition, several simulation scenarios were run in order to explore the impact of the quality of the error model, interoccasion variability (IOV), error in the number of pills taken, and the performance of the Compliance estimation method. Results The best Compliance estimate was obtained with pharmacokinetic samples taken 5 hours after the last dose. Performance of the method varied between simulation scenarios. In both the imatinib and capecitabine basic simulations, Patient Compliance was correctly estimated on the two last scheduled doses (with better results for imatinib). The magnitude of the error model also had a great impact on the quality of the Compliance estimate. Conclusions We highlight the effect of three parameters on the quality of Compliance estimates based on limited pharmacokinetic information: the plasma elimination half-life, interdose interval and magnitude of the error model. Nevertheless, the pharmacokinetic method is not informative enough and should be used with electronic monitoring, which provides additional information on Compliance. Our method will be used in a future phase IV clinical trial where the relationships between Compliance, efficacy and tolerability will be assessed.
Adam F Lindstrom - One of the best experts on this subject based on the ideXlab platform.
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Patient Compliance with orthodontic retainers in the postretention phase
American Journal of Orthodontics and Dentofacial Orthopedics, 2011Co-Authors: Michael C Pratt, Thomas G Kluemper, Adam F LindstromAbstract:INTRODUCTION: Retention is an important, even critical, component of orthodontic treatment. There is little research on practice protocols and Patient Compliance with long-term or short-term retention. This lack of information leaves our specialty with many opinions and practice protocols. The purposes of this study were to evaluate and quantify orthodontic retainer wear according to several variables, including Patient age, sex, time in retention, and retainer type, and to identify predictors of Compliance and reasons for nonCompliance with removable orthodontic retainers. METHODS: Questionnaires were mailed to Patients who finished full fixed appliance therapy in either the orthodontic graduate clinic or the orthodontic faculty practice at the University of Kentucky within the past 6 years. Of the 1085 questionnaires mailed, 280 were returned (25.8%). A logistic regression model that described the probabilities of retainer wear was created (P <0.0001). RESULTS: Patient Compliance was greater with vacuum-formed retainers (VFRs) for the first 2 years after debonding. However, Compliance with VFRs decreased at a much faster rate than with Hawley retainers. Because of this, Patient Compliance was greater with Hawley retainers at any time longer than 2 years after debonding, and Patient Compliance overall was greater with Hawley retainers. CONCLUSIONS: This evidence disagrees with the current anecdotal trend of orthodontists who favor switching from Hawley retainers to VFRs. An unexpected finding was that Patients reported few esthetic concerns about retainers, and the few that were reported were equally distributed between Hawley retainers and VFRs.
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Patient Compliance with orthodontic retainers in the postretention phase
American Journal of Orthodontics and Dentofacial Orthopedics, 2011Co-Authors: Michael C Pratt, G. Thomas Kluemper, Adam F LindstromAbstract:Introduction Retention is an important, even critical, component of orthodontic treatment. There is little research on practice protocols and Patient Compliance with long-term or short-term retention. This lack of information leaves our specialty with many opinions and practice protocols. The purposes of this study were to evaluate and quantify orthodontic retainer wear according to several variables, including Patient age, sex, time in retention, and retainer type, and to identify predictors of Compliance and reasons for nonCompliance with removable orthodontic retainers. Methods Questionnaires were mailed to Patients who finished full fixed appliance therapy in either the orthodontic graduate clinic or the orthodontic faculty practice at the University of Kentucky within the past 6 years. Of the 1085 questionnaires mailed, 280 were returned (25.8%). A logistic regression model that described the probabilities of retainer wear was created ( P Results Patient Compliance was greater with vacuum-formed retainers (VFRs) for the first 2 years after debonding. However, Compliance with VFRs decreased at a much faster rate than with Hawley retainers. Because of this, Patient Compliance was greater with Hawley retainers at any time longer than 2 years after debonding, and Patient Compliance overall was greater with Hawley retainers. Conclusions This evidence disagrees with the current anecdotal trend of orthodontists who favor switching from Hawley retainers to VFRs. An unexpected finding was that Patients reported few esthetic concerns about retainers, and the few that were reported were equally distributed between Hawley retainers and VFRs.
John Urquhart - One of the best experts on this subject based on the ideXlab platform.
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Patient Compliance in rheumatoid arthritis polymyalgia rheumatica and gout
The Journal of Rheumatology, 2003Co-Authors: Erik De Klerk, John Urquhart, Desiree Van Der Heijde, Robert Landewe, Hille Van Der Tempel, Sjef Van Der LindenAbstract:OBJECTIVE: (1) To explore Patient Compliance with prescribed drug regimens in the setting of usual care for outPatients with rheumatoid arthritis (RA), gout, and polymyalgia rheumatica (PMR) by utilizing electronic medication event monitors (MEMS(R)) to register openings of the medication package. (2) To examine the influence of disease, frequency of intake of the drug, and class of drug on Compliance. (3) To explore the influence of demographic factors, quality of life measures, coping, health status, and functional ability as potential predictors of Patient Compliance. METHODS: A total of 127 consenting consecutive Patients were enrolled: 81 Patients with RA, 33 taking nonsteroidal antiinflammatory drugs (13 diclofenac TID and 20 naproxen BID) and 48 taking disease modifying antirheumatic drugs [25 sulfasalazine (SSZ) BID and 23 methotrexate (MTX) once weekly]; 17 Patients with PMR starting with prednisolone QD; and 29 Patients with gout starting with colchicine (12, QD) or starting with uric acid lowering agents (17, QD). All Patients received first prescriptions and were instructed to take the medication as prescribed. Followup was 6 months (gout 12 mo). All Patients were aware of the monitoring capability of the package. At baseline a series of questionnaires was completed. We summarized the dosing histories as "taking Compliance" (percentage of total prescribed doses taken), "correct dosing" (percentage of doses taken as prescribed), and "timing Compliance" (percentage of doses taken within +/- 25% of prescribed interdose intervals). RESULTS: A total of 26,685 days (> 73 Patient-years) were monitored. Compliance expressed as "taking Compliance," mean (95% CI), "correct dosing," mean (95% CI), and "timing Compliance," mean (95% CI) are: naproxen: 82% (75-90), 68% (57-80), 48% (34-61); diclofenac: 77% (61-93), 67% (47-87), 39% (21-57); MTX: 107% (98-117), 81% (75-87), 83% (76-90); SSZ: 72% (60-84), 55% (44-67), 25% (18-33); prednisolone: 96% (89-102), 88% (83-92), 82% (74-89); colchicine: 65% (48-81), 44% (26-62), 32% (18-46); and uric acid lowering agents: 84% (76-92), 74% (63-85), 65% (52-79). Missed doses occurred more frequently than taking of extra doses: in RA, on 10% of all monitored days there was no evidence of dosing, while on 3% of all monitored days extra doses were taken. In PMR and gout these data are 10% and 4%, and 15% and 7%, respectively. We observed a decline of Compliance over time in all study medication groups. Multiple regression analyses showed that the class of medication (symptom modifying or disease controlling), the dosing frequency, the Patient's sex, coping pattern (avoidance, passive reaction pattern, and expression of emotions), and the overall health (total Nottingham Health Profile score) together explained 67% of the variance in taking Compliance (adjusted R2) (p = 0.002). CONCLUSION: Studying Patient Compliance with prescribed drug regimens utilizing electronic medication event monitors in RA, gout, and PMR showed that large differences exist in Compliance between the various medication groups. Compliance declines over time. A regression model shows that it is possible to relate differences in Patient Compliance to a number of medication and Patient related factors.
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Role of Patient Compliance in Clinical Pharmacokinetics
Clinical Pharmacokinetics, 1994Co-Authors: John UrquhartAbstract:Until 1986 to 1987, the estimation of Patient Compliance with prescribed drug regimens in ambulatory care relied on methods that were biased either by their subjectivity or by the improvement in Compliance that commonly occurs during the day or two prior to a scheduled examination, so called ‘white-coat Compliance’. In 1986 to 1987, 2 objective methods were developed: electronic monitoring and low-dose, slow-turnover chemical markers (digoxin or phenobarbital [phenobarbitone]) incorporated into dosage forms. While neither method is without limitations, both have enabled major advances in the understanding of Patients’ Compliance with dosage regimens and, thus, the spectrum of drug exposure in ambulatory care. The new methods have also triggered not only a revival of interest in Patient Compliance and its determinants, but also new statistical approaches to interpreting the clinical correlates of widely variable drug administration, and thus drug exposure, in drug trials. The marker methods prove dose ingestion during the 3 to 7 days prior to blood sampling, but do not reveal the timing of doses. The electronic monitoring methods, i.e. time and date-stamping microcircuitry incorporated into drug packages, provide a continuous record of timing of presumptive doses throughout periods of many months, but do not prove dose ingestion. The electronic record has been judged robust enough to detect certain types of investigator fraud, and to support modelling projections of the complete time course of the plasma drug concentration during a trial. Both marker and electronic methods show that the predominant errors are those of omission, i.e. delays or omissions of scheduled doses. Patient interviews, diaries, and counts of returned, untaken doses have been shown by both marker and electronic monitoring methods to consistently and substantially to overestimate Compliance. Monitoring of plasma drug concentrations also overestimates Compliance, because white-coat Compliance is prevalent, and the pharmacokinetic turnover of most drugs is rapid enough that measured concentrations of drug in plasma reflect only drug administration during the period of white-coat Compliance. Thus, Compliance is a great deal poorer in clinical trials than has been revealed by the older methods. The long-standing underestimation of poor Compliance in drug trials has many implications for the interpretation of drug trials, for optimal dose estimation, for the interpretation of failed drug therapy, and for accurate labelling of prescription drugs.
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role of Patient Compliance in clinical pharmacokinetics
Clinical Pharmacokinectics, 1994Co-Authors: John UrquhartAbstract:Until 1986 to 1987, the estimation of Patient Compliance with prescribed drug regimens in ambulatory care relied on methods that were biased either by their subjectivity or by the improvement in Compliance that commonly occurs during the day or two prior to a scheduled examination, so called ‘white-coat Compliance’.
A Schmassmann - One of the best experts on this subject based on the ideXlab platform.
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wallstents versus plastic stents in malignant biliary obstruction effects of stent patency of the first and second stent on Patient Compliance and survival
The American Journal of Gastroenterology, 1996Co-Authors: A Schmassmann, E Von Gunten, J Knuchel, U Scheurer, H Fehr, F HalterAbstract:Objectives : In prospective trials in Patients with malignant biliary obstruction, it has been reported that Wallstents prolong stent patency, but this does not translate into a significant survival benefit. Compared with prospective trials, however, survival may be different in clinical practice because of differences in Patient Compliance. We report on a retrospective, long term analysis comparing Wallstents versus plastic stents. Methods : Plastic endoprostheses (70 Patients) and endoscopic Wallstents (95 Patients) were placed in 165 consecutive Patients with irresectable, malignant biliary obstruction in a first (1990-91) and second (1992-93) time period. Stent occlusion was treated by plastic stent placement. Results : Patient characteristics were quite comparable in both stent groups. Initial placement of a Wallstent resulted in an increase of median stent patency of the first (10 vs 4 months, p < 0.001) and second (8 vs 3 months, p < 0.05) stent, a decrease of additional endoscopic procedures (20 vs 58%, p < 0.005), an increase of Patient Compliance reflected by a decrease of Patients dying with untreated stent occlusion (9 vs 30%, p < 0.001), and an increase of survival time (6.5 vs 4 months, p < 0.05). Conclusions : Initial placement of a Wallstent results in an increase of stent patency of the first and second stent. Duration of stent patency appears to have a determinant effect on Patient Compliance. Increased stent patency and Patient Compliance seem to improve survival in clinical practice.