Biomedical subjects

Patrick Marquis

Publications and source records attributed to Patrick Marquis.

16 recordsLinked to original sources

PubMed2006

Emotion induction after direct intracerebral stimulations of human amygdala.

Very few studies in humans have quantified the effect obtained after direct electrical stimulation of the amygdala, in terms of both emotional and physiological responses. We tested patients with drug-resistant partial epilepsies who were explored with intracerebral electrodes in the setting of presurgical evaluation. We assessed the effects of direct electric stimulations in either the right or the left amygdala on verbally self-reported emotions (Izard scale) and on psychophysiological markers of emotions by recording skin conductance responses (SCRs) and by measuring the electromyographic responses of the corrugator supercilii (EMGc). According to responses on Izard scales, electrical stimulations of the right amygdala induced negative emotions, especially fear and sadness. In contrast, stimulations of the left amygdala were able to induce either pleasant (happiness) or unpleasant (fear, anxiety, sadness) emotions. Unpleasant states induced by electrical stimulations were accompanied by an increase in EMGc activity. In addition, when emotional changes were reported after electrical stimulation, SCR amplitude for the positively valenced emotions was larger than for the negative ones. These findings provide direct in vivo evidence that the human amygdala is involved in emotional experiences and strengthen the hypothesis of a functional asymmetry of the amygdala for valence and arousal processing.

Adult↗

PubMed2006

Electric source imaging in frontal lobe epilepsy.

The objective of this study was to determine the validity of interictal spike (IIS) source localization in frontal lobe epilepsies (FLE) using stereoelectroencephalography as a validating method. Ten patients with drug-resistant FLE were studied with high-resolution EEG and stereoelectroencephalography. Sixty-four scalp channels, a realistic head model, and different algorithms were used. For each patient, the intracerebral interictal distribution was studied and classified into one of three groups: lateral, medial, and mixed (latero-medio-basal). Surface IIS were abundant or subcontinuous for 8 of 10 FLE patients. In lateral and medial groups, intracerebral interictal activities were accurately localized. In the mixed group, source localizations designated a part of the intracerebral interictal distribution. A high degree of source localization accuracy is obtained in FLE. False-positive results were never obtained, but the extent of interictal activity could be underestimated by source localization results. Geometrical and cytoarchitectonic characteristics of the generator appear crucial to explain why medial frontal IIS (anterior para-cingulate gyrus and anterior cingulate gyrus) may be localizable whereas only the lateral orbitofrontal IIS seems to be localizable.

Adolescent↗

PubMed2005

Cross-cultural validation and analysis of responsiveness of the QUALIOST: QUAlity of Life questionnaire In OSTeoporosis.

BACKGROUND: The QUALIOST was designed for use with the SF-36 to measure established osteoporosis-specific quality of life (QoL). The reliability (internal consistency and test-retest) and validity of the questionnaire were established in a stand-alone psychometric validation study. The objective of this paper is to provide additional information on the instrument's responsiveness using clinical trial data, along with the reliability and validity of translated versions. METHODS: The Spinal Osteoporosis Therapeutic Intervention (SOTI) was an international clinical trial comparing strontium ranelate to placebo on the occurrence of new vertebral fracture in patients with postmenopausal osteoporosis. QoL was a secondary endpoint, assessed using the SF-36 and QUALIOST at baseline and every six months, with the main analysis at 3-year follow-up. Questionnaire acceptability, analysis of the hypothesised structure, internal consistency reliability and responsiveness to clinical change over time were assessed at the 3-year follow up. RESULTS: 1592 patients from 11 countries completed at least one QoL questionnaire. The psychometric properties of the questionnaires were assessed on cross-sectional (N = 1486) and longitudinal (N = 1288) data. Item discriminant validity of the QUALIOST was excellent, as was item convergent validity, with 100% of item-scale correlations being above the 0.40 level. Internal consistency reliability was also extremely good, with high Cronbach's alpha scores above the 0.70 benchmark. Responsiveness results were consistent for all QUALIOST scores, indicating that greater decreases in QoL corresponded to greater numbers of fractures experienced. QUALIOST scores also differed according to the type of fracture suffered. This was demonstrated by increased effect sizes for more severe vertebral fractures (clinical vertebral and painful vertebral). In comparing responsiveness, the QUALIOST scores were generally more consistent than those of the SF-36. Most notably, the QUALIOST was more responsive with regard to painful vertebral fractures than the SF-36. CONCLUSION: The QUALIOST is a reliable and valid tool for measuring QoL in postmenopausal osteoporotic women. Being available in several validated language versions, it is ready to be used in a variety of settings, including international clinical trials.

Activities of Daily Living↗

PubMed2005

The treatment satisfaction scale: a multidimensional instrument for the assessment of treatment satisfaction for erectile dysfunction patients and their partners.

BACKGROUND: The development of the Treatment Satisfaction Scale (TSS) was previously reported (Kubin et al., 2004). OBJECTIVE: This article describes the psychometric validation process and psychometric properties (e.g., reliability, validity, and responsiveness) of TSS. METHODS: Initial patient and partner questionnaires were administered in a multi-national clinical trial. On the basis of exploratory analyses, iterative psychometric testing, and consideration of face validity and interpretability, the number of items was reduced, and six scales were constructed: "Satisfaction with Medication," "Ease with Erection," "Satisfaction with Erectile Function," "Pleasure from Sexual Activity," "Satisfaction with Orgasm," and either "Sexual Confidence" (for patients) or "Confidence in Completion" (for partners). RESULTS: Multi-item scales had good internal consistency reliability and concurrent validity with the IIEF. All patient scales and most partner scales were valid in relation to clinical criteria, and all tested scales were responsive to change over time. CONCLUSION: The TSS is brief, culturally valid, and the most comprehensive multidimensional measure of satisfaction with ED treatment for patients and their partners, and addresses some of the shortcomings of existing measures.

Adult↗

PubMed2005

Role of clinical, patient-reported outcome and medico-economic studies in the public hospital drug formulary decision-making process: results of a European survey.

CONTEXT: Over the past 20 years, drug information has grown rapidly, but little is known of its actual use in hospital decision-making. OBJECTIVE: To describe the role of clinical studies (CS), patient-reported outcome studies (PROS) and medico-economic studies (MES) in public hospital drug formulary decision-making. METHODS: A postal survey was conducted in 400 randomly selected public hospitals stratified by country (France, Germany, The Netherlands and the United Kingdom) and profession (doctor or pharmacist). RESULTS: The participation rate was 78% (143 doctors and 169 pharmacists), and the response rate 44%. Responders were generally interested in CS (86%), PROS (71%) and MES (71%). They reported high but unmet expectations concerning information available on PROS and MES, the methodology of these studies and interpretation of the results. CONCLUSIONS: To increase the impact of PROS and MES, we suggest training decision-makers in the study methodology and provide them with support of health and economic experts.

Clinical Trials as Topic↗

PubMed2005

Relationship between auditory perception skills and mismatch negativity recorded in free field in cochlear-implant users.

This study investigated the ability of cochlear-implanted patients to discriminate tone bursts in free field using the electrophysiological recordings of mismatch negativity (MMN). Seven cochlear-implanted patients (CIP) and eight control subjects (CS) were tested. Event-related potentials were recorded from either 32 or 64 electrodes in response to binaural stimuli using a passive oddball paradigm. Two stimulus-contrast conditions were used to produce MMN: The standard-tone frequency was fixed at 1 kHz, and the deviant-tone frequency was set at 2 or 1.5 kHz. The results show that response waveforms (N1/P2) are similar in latency and amplitude for CS and CIP, suggesting that pure-tone detection is performed over the same time window in both groups. These waveforms are also similar in left- and right-implanted patients, suggesting that electric stimulation of the auditory nerve activates both hemispheres in profound, bilateral hearing loss. Pure-tone audiograms and word-discrimination scores were also measured in each subject in an anechoic room and their relations with MMN data were examined. Correlations were found between the latency of MMN for a 1.5 kHz deviant and the thresholds obtained for pure-tone detection and word discrimination. MMN appears as a possible complementary clinical tool to objectively assess auditory sensitivity in cochlear-implanted populations. However, further improvements are still necessary before it can be used as a standard clinical examination.

Acoustic Stimulation↗

PubMed2005

Development and validation of the Patient Assessment of Constipation Quality of Life questionnaire.

OBJECTIVE: Chronic constipation is characterized by difficult, infrequent, or seemingly incomplete bowel movements. The Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaire was developed to address the need for a standardized, patient-reported outcomes measure to evaluate constipation over time. MATERIAL AND METHODS: Items for the PAC-QOL were generated from the literature, clinical experts, and patients. Following principal components and multi-trait analyses, 28 items were retained forming four subscales (worries and concerns, physical discomfort, psychosocial discomfort, and satisfaction) and an overall scale. Validation studies were conducted in the United States, Europe, Canada, and Australia, to evaluate the internal consistency reliability (Cronbach's alpha), reproducibility (Intraclass Correlation Coefficients (ICCs)), validity (analysis of variance models), and responsiveness (effect size) of the PAC-QOL scales. RESULTS: The PAC-QOL scales were internally consistent (Cronbach's alpha >0.80) and reproducible (ICCs >0.70, except for the satisfaction subscale ICC=0.66). PAC-QOL scale scores were significantly associated with abdominal pain (p<0.001) and constipation severity (p<0.05). Effect sizes in patients reporting improvements in constipation over a 6-week period were moderate to large, with subscale effect sizes ranging from 0.76 to 3.41 and the overall scale effect size=1.77. Similar findings were observed in validation studies conducted in Europe, Canada, and Australia. CONCLUSIONS: The PAC-QOL is a brief but comprehensive assessment of the burden of constipation on patients' everyday functioning and well-being. Multinational studies demonstrate that the PAC-QOL is internally consistent, reproducible, valid, and responsive to improvements over time.

Adult↗

PubMed2004

Cross-cultural development and validation of a patient self-administered questionnaire to assess quality of life in upper gastrointestinal disorders: the PAGI-QOL.

OBJECTIVE: Summarize the Patient Assessment of Upper GastroIntestinal Disorders-Quality of Life (PAGI-QOL) development and provide results on its reliability and validity from the international psychometric validation in dyspepsia, GastroEsophageal Reflux Disease (GERD), and gastroparesis. METHODS: Subjects completed the pilot PAGI-QOL at baseline and 8 weeks; and a subsample also at 2 weeks. Other assessments were: Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index, SF-36, number of disability days. RESULTS: 1736 patients completed the PAGI-QOL at baseline. The questionnaire was reduced, producing a 30-item final version covering five domains: Daily Activities, Clothing, Diet and Food Habits, Relationship (REL), and Psychological Well-Being and Distress. Internal consistency was excellent (Cronbach's alpha range: 0.83-0.96). Test-retest reproducibility was good: intraclass correlations coefficients were over 0.70 except for the REL scale (0.61). Concurrent validity between the PAGI-QOL total score and all SF-36 subscale scores was good with moderate (0.52) to strong (0.72) correlations. PAGI-QOL scores showed excellent discriminant properties: patients who had spent some days in bed, had missed some days at work, and were kept from usual activities had much lower PAGI-QOL scores than those who did not (p < 0.0001). CONCLUSION: The PAGI-QOL is a valid and reliable instrument assessing quality of life in patients with dyspepsia, GERD, or gastroparesis.

Cross-Cultural Comparison↗

PubMed2004

Development and validation of the Pain Treatment Satisfaction Scale (PTSS): a patient satisfaction questionnaire for use in patients with chronic or acute pain.

The purpose of this study was to develop and validate a measure of patient satisfaction for patients receiving treatment for either acute or chronic pain: the Pain Treatment Satisfaction Scale (PTSS). Development of the initial questionnaire included a comprehensive literature review and interviews with patients, physicians and nurses in the United States, Italy and France. After initial items were created, psychometric validation was run on responses from 111 acute pain and 89 chronic pain patients in the United States. Analyses included principal components factor analysis tests of reliability, clinical validity and confounding. The hypothesized structure of the questionnaire was supported by statistical analyses, and seven overlapping or inconsistent items were removed. The multi-item domains of the final PTSS included 39 items grouped in five dimensions: information (5 items); medical care (8 items); impact of current pain medication (8 items); satisfaction with pain medication which included the two subscales medication characteristics (3 items) and efficacy (3 items); and side effects (12 items). Internal consistency reliability coefficients were good (ranging from 0.83 to 0.92). The test-retest reliability coefficients (ranging from 0.67 to 0.81) were good for all dimensions except medication characteristics (0.55). All dimensions except medical care discriminated well according to pain severity. The satisfaction with efficacy dimension, hypothesized to change in the acute pain population, indicated good preliminary responsiveness properties (effect size 0.37; P<0.001). The PTSS is a valid, comprehensive instrument to assess satisfaction with treatment of pain based on independent modules that have demonstrated satisfactory psychometric performance.

Female↗

PubMed2004

Responsiveness and interpretation of a quality of life questionnaire specific to upper gastrointestinal disorders.

BACKGROUND AND AIMS: The Patient Assessment of Upper Gastrointestinal Disorders-Quality of Life (PAGI-QOL) has been developed and validated to assess quality of life in gastroesophageal reflux disease, dyspepsia, and gastroparesis. The aim of this work was to assess responsiveness of the PAGI-QOL to clinical changes and provide guidance for the interpretation of score changes. METHODS: The analysis was based on 2 observational multicenter, longitudinal, 8-week observation studies, one in the United States and one in 5 European countries. The Overall Treatment Effect scale completed by patients and clinicians at 8 weeks was used to define groups of improved, worsened, and stable patients. Responsiveness was assessed by describing the change in PAGI-QOL scores for each of these groups, comparing these changes over time, and calculating effect sizes and standardized response means. These data were used to define the minimal clinically important difference. RESULTS: A total of 1736 patients with upper gastrointestinal disorders were analyzed. High sensitivity to change over time was demonstrated, with effect sizes and standardized response means in improved patients for the PAGI-QOL total score ranging from 0.79-1.41. A change of 0.4 for the PAGI-QOL total score might be considered as the minimal clinically important difference when comparing pretreatment and post-treatment PAGI-QOL total scores. CONCLUSIONS: The PAGI-QOL questionnaire is a responsive and clinically relevant instrument for assessing quality of life in patients with upper gastrointestinal disorders.

Adolescent↗

PubMed2003

Quality of life in patients with stomas: the Montreux Study.

Ostomy surgery profoundly affects a person's life. To determine the extent of the effect, the Stoma Care Quality of Life Index instrument was developed from a quality-of-life index. After ascertaining its validity and reliability, the instrument was used to measure patient quality of life in a European-wide study (16 countries). Six hundred, eighteen (618) stoma care nurses recruited 4,739 patients following stoma surgery. The self-administered questionnaire was completed immediately following surgery and after 3,6, 9, and 12 months. The mean age of patients was 61.6 years (+/- 13.4 years), 53.7% were men, and the majority (66.5%) had a colostomy. Stoma Care Quality of Life Index scores were fairly consistent in all patients throughout Europe immediately following surgery. While scores improved steadily over time, only the difference between the postoperative and 3-month scores was significant (P < 0.001). Stoma Care Quality of Life Index scores were significantly higher in patients who were satisfied with the care received than in those who were not satisfied. Similarly, patients who had a good relationship with the stoma care nurse and felt confident about changing the appliance had significantly higher Stoma Care Quality of Life Index scores than those who did not have a good relationship or feel confident. The results of this study suggest that stoma patient quality of life can be assessed, that it changes over time, and that patient access to specialist ostomy care nurses is particularly important during the first 3 to 6 months following surgery.

Aged↗

PubMed2002

The community-acquired pneumonia symptom questionnaire: a new, patient-based outcome measure to evaluate symptoms in patients with community-acquired pneumonia.

STUDY OBJECTIVE: s: To develop and validate a patient-based outcome measure to evaluate symptoms in patients with community-acquired pneumonia (CAP). DESIGN: A psychometric study within an international, prospective, randomized, double-blind study. The CAP-symptom questionnaire (CAP-Sym) is a new, 18-item, patient-reported outcome measure that evaluates the bothersomeness of CAP-related symptoms during the past 24 h using a 6-point Likert scale. We used "gold standard" psychometric methods to comprehensively evaluate the acceptability, reliability, validity, and responsiveness of the CAP-Sym. SETTING: Sixty-four centers in 13 countries (France, Germany, Hungary, Israel, Italy, Norway, Poland, Portugal, South Africa, Spain, Sweden, Switzerland, United Kingdom). PATIENTS: Five hundred fifty-six patients with CAP, recruited from outpatient clinics, general practice, and hospital centers. INTERVENTIONS: Randomization 1:1 to moxifloxacin (400 mg once daily), oral or standard oral treatment (amoxicillin, 1 g tid, or clarithromycin, 500 mg bid), alone or in combination, for up to 14 days. RESULTS: Standard psychometric tests confirmed the acceptability (item nonresponse, item-endorsement frequencies, item/scale floor and ceiling effects), reliability (internal consistency, item-total and inter-item correlations, test-retest reliability), validity (content, construct, convergent, discriminant, known groups), and responsiveness of the CAP-Sym. CONCLUSIONS: The CAP-Sym is a practical and scientifically sound patient-based outcome measure of CAP-related symptoms that has been developed using "gold standard" methods. As the only fully validated measure of symptoms in patients with CAP, which is quick and easy to administer and is more responsive than the generic Medical Outcomes Study 36-Item Short-Form Health Survey, the CAP-Sym provides a practical and rigorous method for improving the evaluation of outcomes in clinical trials and audit.

Adult↗

PubMed2002

The clinical significance of quality-of-life results: practical considerations for specific audiences.

This is the sixth article in a series intended to summarize the state of the science for assessing the clinical significance of quality-of-life (QOL) assessments. The previous 5 articles dealt with specific methodological issues, whereas this article addresses practical considerations in implementing the methods and presenting the results to various audiences with differing perspectives. Proposals for how to interpret the "clinical significance" or "clinical meaningfulness" of changes in QOL scores were addressed in previous articles within this series. Within this article, 4 audiences-patients and physicians, clinical researchers, health policymakers, and private- and public-sector employees who work in health-related fields-are examined because each is a unique stakeholder with a distinct vantage point and each can interpret QOL outcomes differently. A clinician may attempt to explain to a patient potential treatment alternatives for his or her QOL; a health policymaker may try to describe to elected officials the financial impact on a patient population with reduced QOL; a researcher may try to obtain the vital messages from a clinical trial that included QOL end points; and a regulatory agency and/or pharmaceutical company may try to ascertain the appropriate level of evidence required for a successful research study. For each of the 4 audiences, concrete examples and practical guidelines are offered by which changes in QOL outcomes can be interpreted meaningfully. Ultimately, both determining and disseminating the meaning of clinical significance are functions of the outlook of the audience because the perspective of the audience determines its ability to comprehend, evaluate, and convey the context within which such outcomes appear meaningful. Among the audiences described within this article, a commonality of interests exist that mandates a careful exposition of the scientific rigor involved in describing the clinical significance of QOL assessments. Collectively, this series attempts to provide methods and means for making such determinations.

Clinical Competence↗

PubMedDate not supplied

Incorporating the patient's perspective into drug development and communication: an ad hoc task force report of the Patient-Reported Outcomes (PRO) Harmonization Group meeting at the Food and Drug Administration, February 16, 2001.

BACKGROUND: The extent to which patient-based outcomes can be used to evaluate and communicate the effect of new drugs and devices is a subject of much debate. Criteria for evaluating the scientific quality of data to support health-related quality of life (HRQL) and other patient-based labeling and promotional claims in the United States and Europe have been proposed by various scientists and organizations. Since March 2000, a working group composed of members of the International Society for Quality of Life Research (ISOQOL), the International Society for Pharmacoeconomics and Outcomes Research (ISPOR), the Pharmaceutical Manufacturer's Association Health Outcomes Committee (PhRMA-HOC), and the European Regulatory Issues on Quality of Life Assessment (ERIQA) met to discuss and coordinate the various recommendations by their respective groups and address the need to harmonize outcomes review criteria within and across United States and European regulatory agencies. Over time, the discussion expanded from HRQL outcomes to include any outcome based on data provided by the patient or patient proxy, that is, patient-reported outcomes (PROs). The working group therefore became known as the PRO Harmonization Group. METHODS: Working with a member of the US Food and Drug Administration (FDA), four key issues requiring clarification were identified: how PROs are defined and put into operation for research purposes; the added value of PROs in the drug review and evaluation process; selected questions related to the PRO measurement and research methodology; and the interest and demand for PRO information by decision makers. On February 15, 2001, all members of the PRO Harmonization Group attended a meeting in Rockville, Maryland, to discuss these four issues further, and on February 16, 2001, a formal presentation was made to representatives from various departments and reviewing divisions of the FDA. These presentations are summarized in this report. RESULTS: All participants agreed that PROs are important for understanding the impact of treatment on patient functioning and well-being. They also stressed the need to communicate PRO information to key decision makers, including regulatory agencies, clinicians, patients and their families, and payers. Finally, the meeting resulted in plans for continuing the dialogue on PRO measurement and interpretation. SUMMARY: The February 16, 2001, meeting represented an important step in harmonizing efforts across various organizations and in opening a dialogue with the FDA around major issues related to methodologic standards for measuring and interpreting PROs in the drug evaluation process.

Advisory Committees↗

PubMedDate not supplied

Electric source imaging in temporal lobe epilepsy.

The objective of this study was to determine the validity of interictal spike (IIS) source localization in temporal lobe epilepsies (TLE) using stereoelectroencephalography as a validating method. Twenty patients with drug-resistant TLE were studied with high-resolution EEG and stereoelectroencephalography. Sixty-four scalp channels, a realistic head model, and different algorithms were used. For each patient, the intracerebral interictal distribution was studied and classified into one of three groups: L (mainly lateral), ML (mediolateral), and M (medial). In group L (three patients), surface IIS were recorded with a high signal-to-noise ratio. Source localizations designated all or part of the intracerebral interictal distribution. In group ML (11 patients), 8 patients had surface IIS, only 5 of which were localizable. High-resolution EEG permitted localization of the more lateral portion and definition of its rostrocaudal extension. A common pattern was identified in three patients with a predominant role of the temporal pole. In group M (six patients), four patients had rare surface IIS, none of which were localizable. Surface EEG does not record IIS limited to medial temporal lobe structures. In TLE with a mediolateral or a lateral interictal distribution, only the lateral component is detectable on surface EEG and accurately localizable by source localization tools.

Adolescent↗

PubMedDate not supplied

A comprehensive strategy for the interpretation of quality-of-life data based on existing methods.

OBJECTIVES: Health-related quality of life (HRQL) instruments generally undergo a rigorous development and validation process. In contrast, methods for interpreting HRQL data are varied, and no comprehensive widely applicable procedure exists. Determining whether differences are statistically significant is the most common method, but this yields conclusions that may be difficult to understand in a clinical context or which may be of no practical value. Consequently, there is a need for a comprehensive interpretation strategy that gives results that are meaningful to a variety of audiences, including patients, clinicians, and decision-makers. METHODS: The review of available interpretation strategies revealed that not all methods are applicable to all questionnaires, and some strategies may be difficult to implement for interpreting trial results. In addition, the issues decision-makers may have when assessing HRQL results have not really been addressed: what is measured and what is the meaning beyond statistical significance? RESULTS: A comprehensive stepwise strategy, based on the most effective methods available, has been developed to address the key interpretation issues of decision-makers. It is structured around several steps: understanding the content of the questionnaire; evaluating the magnitude of changes and their statistical significance; determining whether results are clinically significant, e.g., whether the observed changes crossed ranges of established threshold for meaningful differences; comparing pre- and post-treatment scores distribution with norms of references; and relating score changes to other outcomes end points such as morbidity, death, compliance, resource utilization, or productivity. CONCLUSIONS: The proposed strategy should help to structure and successfully address interpretation issues and thus make HRQL results more convincing.

Data Interpretation, Statistical↗