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D Laurent

Publications and source records attributed to D Laurent.

At least 163 records · Page 9Linked to original sources

Capturing the patient's view of change as a clinical outcome measure.

CONTEXT: Measurement of change in patients' health status is central to both clinical trials and clinical practice. Trials commonly use serial measurements by the patients at 2 points in time while clinicians use the patient's retrospective assessment of change made at 1 point in time. How well these measures correlate is not known. OBJECTIVE: To compare the 2 methods in measurement of changes in pain and disability. DESIGN: Longitudinal survey of patients starting new therapy for chronic arthritis in 1994 and 1995. Surveys were completed at baseline (before intervention) and at 6 weeks and 4 months. SETTING: Community health education program and university medical and orthopedic services. SUBJECTS: A total of 202 patients undertaking self-management education (n = 140), therapy with prednisone or methotrexate (n = 34), or arthroplasty of the knee or hip (n = 28). MAIN OUTCOME MEASURES: Concordance between serial (visual analog scale for pain and Health Assessment Questionnaire for disability) and retrospective (7-point Likert scale) measures, sensitivities of these measures, and their correlation with patients' satisfaction with the change (7-point Likert scale). RESULTS: When change was small (education group), serial measures correlated poorly with retrospective assessments (eg, r=0.13-0.21 at 6 weeks). With greater change, correlations improved (eg, r = 0.45-0.71 at 6 weeks). Average agreement between all pairs of assessments was 29%. Significant lack of concordance was confirmed in all 12 comparisons by McNemar tests (P = .02 to <.001) and by t tests (P = .03 to <.001). Retrospective measures were more sensitive to change than serial measures and correlated more strongly with patients' satisfaction with change. CONCLUSION: The 2 methods for measuring health status change did not give concordant results. Including patient retrospective assessments in clinical trials might increase the comprehensiveness of information gained and its accord with clinical practice.

Aged↗

[Retrospective analysis of the reproducibility of the daily set-up of the irradiation fields of cancer of the rectum using a megavoltage imaging system].

PURPOSE: To evaluate a ionization chamber on-line portal imaging system in routine clinical radiotherapy of rectum cancers. PATIENTS AND METHODS: Megavolt portal images were obtained using a fast electronic megavoltage radiotherapy imaging system in 13 cases of pelvic fields. A total of 208 portal images and 13 simulator films were used to determine the values of set-up deviations in the X-Z-directions of a fixed co-ordinate system, and of the rotation fields (R). RESULTS: Mean standard deviations of the difference between simulation and treatment images were 3.2 mm and 0.9 mm for X and Z, 3.6 mm for the rotation fault. The standard deviations were, respectively, 7.1 mm, 7.1 mm and 1.5 mm. The cumulative frequency distributions revealed that 80% and 95% of the absolute differences were less than 10 mm and 17.5 mm, respectively. CONCLUSION: These results indicate the difficulty of a reproducible daily set-up. A weekly control could be proposed in order to increase the quality of pelvic site treatment. The introduction of masks to improve the set-up is also discussed.

Humans↗

[In vitro study of a paclitaxel-radiotherapy combination on a human epidermoid tumor cell line].

PURPOSE: Paclitaxel is an agent which stabilizes microtubules, and has been shown to block different cells in the G2/M phase of the cell cycle and thus to modulate their radioresponsiveness. We investigated the radiosensitizing potential of paclitaxel in human head and neck cancer cells. MATERIALS AND METHODS: ZMK-1 cells were incubated with paclitaxel for 3, 9, or 24 h before or during 24 h after irradiation. Paclitaxel concentrations of 70 nM, 7 nM, and 0.7 nM were chosen to obtain equivalent toxicity at the different incubation times: 3 h, 9 h, and 24 h, respectively. Radiation doses ranged from 0 to 8 Gy using 60Co source. Cell survival was measured by a standard clonogenic assay after a 9-day incubation. Flow cytometry was used to measure the capacity of paclitaxel to accumulate cells in the G2/M phase. RESULTS: Paclitaxel alone possessed cytotoxicity dependent on time and concentration. There was a total of 40% of cells accumulated in G2/M after 24-36 h. When combined with radiation, the 9 h preincubation resulted in a radiosensitization. The 3 h pre-incubation as well as the 24 h post-incubation resulted in an infra-additive effect. CONCLUSION: In our cells a radiosensitizing effect of paclitaxel could not be demonstrated unambiguously. The blockage of the cells in the G2/M phase is not the only mechanism to explain the potential radiosensitization of paclitaxel.

Drug Screening Assays, Antitumor↗

Effect of a self-management program on patients with chronic disease.

CONTEXT: For patients with chronic disease, there is growing interest in "self-management" programs that emphasize the patients' central role in managing their illness. A recent randomized clinical trial demonstrated the potential of self-management to improve health status and reduce health care utilization in patients with chronic diseases. OBJECTIVE: To evaluate outcomes of a chronic disease self-management program in a real-world" setting. STUDY DESIGN: Before-after cohort study. PATIENTS AND SETTING: Of the 613 patients from various Kaiser Permanente hospitals and clinics recruited for the study, 489 had complete baseline and follow-up data. INTERVENTION: The Chronic Disease Self-Management Program is a 7-week, small-group intervention attended by people with different chronic conditions. It is taught largely by peer instructors from a highly structured manual. The program is based on self-efficacy theory and emphasizes problem solving, decision making, and confidence building. MAIN OUTCOME MEASURES: Health behavior, self-efficacy (confidence in ability to deal with health problems), health status, and health care utilization, assessed at baseline and at 12 months by self-administered questionnaires. RESULTS: At 1 year, participants in the program experienced statistically significant improvements in health behaviors (exercise, cognitive symptom management, and communication with physicians), self-efficacy, and health status (fatigue, shortness of breath, pain, role function, depression, and health distress) and had fewer visits to the emergency department (ED) (0.4 visits in the 6 months prior to baseline, compared with 0.3 in the 6 months prior to follow-up; P = 0.05). There were slightly fewer outpatient visits to physicians and fewer days in hospital, but the differences were not statistically significant. Results were of about the same magnitude as those observed in a previous randomized, controlled trial. Program costs were estimated to be about $200 per participant. CONCLUSIONS: We replicated the results of our previous clinical trial of a chronic disease self-management program in a "real-world" setting. One year after exposure to the program, most patients experienced statistically significant improvements in a variety of health outcomes and had fewer ED visits.

California↗