230 research outputs found

    Analyzing the effects of past prices on reference price formation

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    We propose a new reference price framework for brandchoice. In this framework, we employ a Markov-switching processwith an absorbing state to model unobserved price recall ofhouseholds. Reference prices result from the prices households areable to remember. Our model can be used to learn how many pricesobserved in the past are used for reference price formation.Furthermore, we learn to what extent households have sufficientprice knowledge to form an internal reference price. For A.C.Nielsen scanner panel data on catsup purchases, we find that theprices observed at the previous purchase occasion have an averagerecall probability of about 20%. Furthermore, the averageprobability that a household has sufficient price knowledge toform a reference price is estimated at about 30%. Even thoughprice recall is very limited the impact of reference priceformation on brand choice is substantial, and it is stronger thantwo popular alternative models in the literature suggest.Moreover, contrary to the two alternative models, our model doesnot suggest asymmetry between price gains and losses.brand choice;household scanner panel data;Markov switching process;reference price

    Analyzing the effects of past prices on reference price formation

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    We propose a new reference price framework for brand choice. In this framework, we employ a Markov-switching process with an absorbing state to model unobserved price recall of households. Reference prices result from the prices households are able to remember. Our model can be used to learn how many prices observed in the past are used for reference price formation. Furthermore, we learn to what extent households have sufficient price knowledge to form an internal reference price. For A.C. Nielsen scanner panel data on catsup purchases, we find that the prices observed at the previous purchase occasion have an average recall probability of about 20%. Furthermore, the average probability that a household has sufficient price knowledge to form a reference price is estimated at about 30%. Even though price recall is very limited the impact of reference price formation on brand choice is substantial, and it is stronger than two popular alternative models in the literature suggest. Moreover, contrary to the two alternative models, our model does not suggest asymmetry between price gains and losses

    Patient’s satisfaction beyond hand function in Dupuytren’s disease: analysis of 1106 patients

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    This study investigates the outcomes of 1106 patients with Dupuytren’s disease treated with limited fasciectomy or percutaneous needle fasciotomy over 16 years according to the different domains of patient-reported hand function. These patients completed the Michigan Hand Outcomes Questionnaire before and 3 months after surgery. Scores for the various outcome parameters were calculated and linear regression analyses were used to examine associations between the changes in digital extension d

    Better patients’ treatment experiences are associated with better postoperative results in Dupuytren’s disease

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    This prospective study investigates the extent to which a better experience with healthcare delivery is associated with better postoperative treatment outcomes after surgery for Dupuytren’s contracture. Patients undergoing limited fasciectomy or percutaneous needle fasciotomy for Dupuytren’s contractures completed the Michigan Hand Outcomes Questionnaire before and 3 months after surgery, together with a patient reported experience measu

    The Ultrashort Mental Health Screening Tool Is a Valid and Reliable Measure With Added Value to Support Decision-making

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    BACKGROUND: Mental health influences symptoms, outcomes, and decision-making in musculoskeletal healthcare. Implementing measures of mental health in clinical practice can be challenging. An ultrashort screening tool for mental health with a low burden is currently unavailable but could be used as a conversation starter, expectation management tool, or decision support tool.QUESTIONS/PURPOSES: (1) Which items of the Pain Catastrophizing Scale (PCS), Patient Health Questionnaire (PHQ-4), and Brief Illness Perception Questionnaire (B-IPQ) are the most discriminative and yield a high correlation with the total scores of these questionnaires? (2) What is the construct validity and added clinical value (explained variance for pain and hand function) of an ultrashort four-item mental health screening tool? (3) What is the test-retest reliability of the screening tool? (4) What is the response time for the ultrashort screening tool?METHODS: This was a prospective cohort study. Data collection was part of usual care at Xpert Clinics, the Netherlands, but prospective measurements were added to this study. Between September 2017 and January 2022, we included 19,156 patients with hand and wrist conditions. We subdivided these into four samples: a test set to select the screener items (n = 18,034), a validation set to determine whether the selected items were solid (n = 1017), a sample to determine the added clinical value (explained variance for pain and hand function, n = 13,061), and a sample to assess the test-retest reliability (n = 105). Patients were eligible for either sample if they completed all relevant measurements of interest for that particular sample. To create an ultrashort screening tool that is valid, reliable, and has added value, we began by picking the most discriminatory items (that is, the items that were most influential for determining the total score) from the PCS, PHQ-4, and B-IPQ using chi-square automated interaction detection (a machine-learning algorithm). To assess construct validity (how well our screening tool assesses the constructs of interest), we correlated these items with the associated sum score of the full questionnaire in the test and validation sets. We compared the explained variance of linear models for pain and function using the screening tool items or the original sum scores of the PCS, PHQ-4, and B-IPQ to further assess the screening tool's construct validity and added value. We evaluated test-retest reliability by calculating weighted kappas, ICCs, and the standard error of measurement.RESULTS: We identified four items and used these in the screening tool. The screening tool items were highly correlated with the PCS (Pearson coefficient = 0.82; p &lt; 0.001), PHQ-4 (0.87; p &lt; 0.001), and B-IPQ (0.85; p &lt; 0.001) sum scores, indicating high construct validity. The full questionnaires explained only slightly more variance in pain and function (10% to 22%) than the screening tool did (9% to 17%), again indicating high construct validity and much added clinical value of the screening tool. Test-retest reliability was high for the PCS (ICC 0.75, weighted kappa 0.75) and B-IPQ (ICC 0.70 to 0.75, standard error of measurement 1.3 to 1.4) items and moderate for the PHQ-4 item (ICC 0.54, weighted kappa 0.54). The median response time was 43 seconds, against more than 4 minutes for the full questionnaires.CONCLUSION: Our ultrashort, valid, and reliable screening tool for pain catastrophizing, psychologic distress, and illness perception can be used before clinician consultation and may serve as a conversation starter, an expectation management tool, or a decision support tool. The clinical utility of the screening tool is that it can indicate that further testing is warranted, guide a clinician when considering a consultation with a mental health specialist, or support a clinician in choosing between more invasive and less invasive treatments. Future studies could investigate how the tool can be used optimally and whether using the screening tool affects daily clinic decisions.LEVEL OF EVIDENCE: Level II, diagnostic study.</p

    Prevalence of post-traumatic neuropathic pain after digital nerve repair and finger amputation

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    Introduction: Post-traumatic neuropathic pain is a major factor affecting the quality of life after finger trauma and is reported with considerable variance in the literature. This can partially be attributed to the different methods of determining neuropathic pain. The Douleur Neuropathique 4 (DN4) has been validated to be a reliable and non-invasive tool to assess the presence of neuropathic pain. This study investigated the prevalence of neuropathic pain after finger amputation or digital nerve repair using the DN4 questionnaire. Methods: Patients with finger amputation or digital nerve repair were identified between 2011 and 2018 at our institution. After a minimal follow-up of 12 months, the short form DN4 (S-DN4) was used to assess neuropathic pain. Results: A total of 120 patients were included: 50 patients with 91 digital amputations and 70 patients with 87 fingers with digital nerve repair. In the amputation group, 32% of the patients had pain, and 18% had neuropathic pain. In the digital nerve repair group, 38% of the patients had pain, and 14% had neuropathic pain. Secondly, of patient-, trauma-, and treatment-specific factors, only the time between trauma and surgery had a significant negative influence on the prevalence of neuropathic pain in patients with digital nerve repair. Conclusion: This study shows that persistent pain and neuropathic pain are common after finger trauma with nerve damage. One of the significant prognostic factors in developing neuropathic pain is treatment delay between trauma and time of digital nerve repair, which is of major clinical relevance for surgical planning of these injuries.</p

    Factors affecting return to work after surgical treatment of trapeziometacarpal joint osteoarthritis

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    This study aimed to identify factors contributing to the timing of return to work after surgical treatment of trapeziometacarpal joint osteoarthritis and to calculate the costs of lost productivity. We included 627 patients with paid employment who underwent trapeziectomy and ligament reconstruction with tendon interposition. Time to return to work was measured through filling online questionnaires and analysed using survival analysis at 6 weeks and 3, 6 and 12 months after the surgery. Patients also filled in the Michigan Hand Outcomes Questionnaire. Costs of lost productivity were calculated using the human capital method. After 1 year, 78% of the patients returned to work. The median time to return to work was 12 weeks. Factors that significantly affected the time to return to work were occupational intensity (light, moderate or heavy physical labour), whether the dominant hand was treated and the Michigan Hand Outcomes Questionnaire work score and hand functi

    Preoperative Indicators of the Effectiveness of Surgical Release in Patients with de Quervain Disease:A Prospective Cohort Study

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    Background: A significant proportion of patients report persistent pain after surgical release for de Quervain disease (DQ). This study aimed to investigate the effectiveness of a surgical release for DQ and to identify the preoperative factors associated with pain after a surgical release for DQ. Methods: This prospective cohort study included 707 patients who underwent surgical release and completed a visual analogue scale questionnaire (VAS; range 0 to 100). We used a paired t test to analyze the effectiveness of the surgical release on pain at 3 months postoperatively compared with the preoperative measure. A hierarchical multivariable linear regression model was created to investigate the contribution of patient-related and disease-related characteristics to postoperative pain. Results: All VAS domains showed improvement after surgical release. On average, the mean VAS pain decreased by 44 points (95% CI, 42, 46). Smoking (B = 6.37; P &lt; 0.01), younger age (B = -0.35; P &lt; 0.01), longer duration of complaints (B = 0.13; P &lt; 0.01), concomitant surgery (B = 14.40; P &lt; 0.01), and higher VAS pain scores at intake (B = 0.15; P &lt; 0.01) were associated with worse VAS pain scores postoperatively. Together, the variables explained 11% of the variance in mean VAS pain score at 3 months follow-up. Conclusions: This study confirms that surgical treatment for DQ significantly reduces patient-reported pain. Smoking, younger age, concomitant surgery, duration of complaints, and higher VAS pain scores at intake are associated with worse patient-reported pain 3 months after surgical release. However, the small effects suggest that these factors should not be considered the only important factors. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.</p

    Determination of the Michel Parameters rho, xi, and delta in tau-Lepton Decays with tau --> rho nu Tags

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    Using the ARGUS detector at the e+ee^+ e^- storage ring DORIS II, we have measured the Michel parameters ρ\rho, ξ\xi, and ξδ\xi\delta for τ±l±ννˉ\tau^{\pm}\to l^{\pm} \nu\bar\nu decays in τ\tau-pair events produced at center of mass energies in the region of the Υ\Upsilon resonances. Using τρν\tau^\mp \to \rho^\mp \nu as spin analyzing tags, we find ρe=0.68±0.04±0.08\rho_{e}=0.68\pm 0.04 \pm 0.08, ξe=1.12±0.20±0.09\xi_{e}= 1.12 \pm 0.20 \pm 0.09, ξδe=0.57±0.14±0.07\xi\delta_{e}= 0.57 \pm 0.14 \pm 0.07, ρμ=0.69±0.06±0.08\rho_{\mu}= 0.69 \pm 0.06 \pm 0.08, ξμ=1.25±0.27±0.14\xi_{\mu}= 1.25 \pm 0.27 \pm 0.14 and ξδμ=0.72±0.18±0.10\xi\delta_{\mu}= 0.72 \pm 0.18 \pm 0.10. In addition, we report the combined ARGUS results on ρ\rho, ξ\xi, and ξδ\xi\delta using this work und previous measurements.Comment: 10 pages, well formatted postscript can be found at http://pktw06.phy.tu-dresden.de/iktp/pub/desy97-194.p

    Positive experience with treatment is associated with better surgical outcome in trapeziometacarpal osteoarthritis

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    The aim of this study was to investigate the association between patients’ experiences with trapeziometacarpal arthroplasty and treatment outcomes in terms of patient-reported outcome measures, grip and pinch strength. We included 233 patients who received a Weilby procedure for trapeziometacarpal osteoarthritis. Before surgery and 12 months after surgery, patients completed the Michigan Hand Outcomes Questionnaire, and their pinch and grip strengths were measured. At 3 months after surgery, a patient-reported experience measure was completed. Using regression analysis, significantly positive associations were found between the Michigan Hand questionnaire and the patient-reported experience measure, with the strongest significant associations being for patients’ experiences with information provision. No significant associations were found between the patients’ experience and strength outcomes. The results highlight the potential importance of positive experience with the treatment process to improve treatment outcomes in patients undergoing surgery for trapeziometacarpal osteoarthritis. Level of evidence: IV
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