| 1. |
- Memedi, Mevludin, 1983-, et al.
(author)
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A web application for follow-up of results from a mobile device test battery for Parkinson’s disease patients
- 2011
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In: Computer Methods and Programs in Biomedicine. - Amsterdam : Elsevier BV. - 0169-2607 .- 1872-7565. ; 104:2, s. 219-226
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Journal article (peer-reviewed)abstract
- A test battery consisting of self-assessments and motor tests for patients with Parkinson’s disease (PD) was constructed and implemented on a hand computer with touch screen in a telemedicine setting. In this work, a Web-based system was developed to deliver decision support information to treating clinical staff for assessing PD symptoms in their patients. Test results from the hand unit are transferred to a central server and processed into scores for different symptom dimensions and an “overall test score” reflecting the overall condition of the patient during a test period. The IBM Computer System Usability Questionnaire was administered to assess the users’ satisfaction with the system. Results showed that a majority of users who completed the evaluation were quite satisfied with the usability although a sizeable minority were not. Response times were tested by simulating up to 100 users accessing the web application at the same time. The average page completion times were in the range of 0.5 seconds indicating fast response. The system was able to summarize the test-battery data and present them in a useful manner. Its main contribution is a novel way to easily access symptom information from the home environment of patients.
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| 2. |
- Westin, Jerker, 1971-, et al.
(author)
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A home environment test battery for status assessment in patients with advanced Parkinson's disease
- 2010
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In: Computer Methods and Programs in Biomedicine. - : Elsevier BV. - 0169-2607 .- 1872-7565. ; 98:1, s. 27-35
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Journal article (peer-reviewed)abstract
- A test battery for assessing patient state in advanced Parkinson's disease, consisting of self-assessments and motor tests, was constructed and implemented on a hand computer with touch screen in a telemedicine setting. The aim of this work was to construct an assessment device, applicable during motor fluctuations in the patient's home environment. Selection of self-assessment questions was based on questions from an e-diary, previously used in a clinical trial. Both un-cued and cued tapping tests and spiral drawing tests were designed for capturing upper limb stiffnes, slowness and involuntary movements. The patient interface gave an audible signal at scheduled response times and was locked otherwise. Data messages in an XML-format were sent from the hand unit to a central server for storage, processing and presentation. In tapping tests, speed and accuracy were calculated and in spiral tests, standard deviation of frequency filtered radial drawing velocity was calculated. An overall test score, combining repeated assessments of the different test items during a test period, was defined based on principal component analysis and linear regression. An evaluation with two pilot patients before and after receiving new types of treatments was performed. Compliance and usability was assessed in a clinical trial (65 patients with advanced Parkinson's disease) and correlations between different test items and internal consistency were investigated. The test battery could detect treatment effect in the two pilot patients, both in self-assessments, tapping tests' results and spiral scores. It had good patient compliance and acceptable usability according to nine nurses. Correlation analysis showed that tapping results provided different information as compared to diary responses. Internal consistency of the test battery was good and learning effects in the tapping tests were small.
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| 3. |
- Westin, Jerker, 1971-, et al.
(author)
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A pharmacokinetic-pharmacodynamic model for duodenal levodopa infusion
- 2011
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In: Clinical neuropharmacology. - Lippincott : Williams & Wilkins. - 0362-5664 .- 1537-162X. ; 34:2, s. 61-65
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Journal article (peer-reviewed)abstract
- Objective: The purpose of this work was to identify and estimate a population pharmacokinetic-pharmacodynamic model for duodenal infusion of a levodopa/carbidopa gel (Duodopa) to examine pharmacological properties of this treatment. Methods: The modeling involved pooling data from 3 studies (on advanced Parkinson disease) and fixing some parameters to values found in literature. The first study involved 12 patients studied on 3 occasions each and was previously published. The second study involved 3 patients on 2 occasions. A bolus dose was given after a washout during night. Plasma samples and motor ratings (clinical assessment of motor function on a 7-point treatment response scale ranging from "very off" to "very hyperkinetic") were collected until the clinical effect returned to baseline. The third study involved 5 patients on 3 occasions receiving 5 different dose levels. Different structural models were evaluated using the nonlinear mixed-effects modeling program NONMEM VI. Population mean parameter values, and interindividual, interoccasion, and residual variabilities were estimated. Results: Absorption of the levodopa/carbidopa gel can be adequately described with first-order absorption with bioavailability and lag time. Estimated population parameter values were a mean absorption time of 28.5 minutes, a lag time of 2.9 minutes, and a bioavailability of 88%. The pharmacodynamic model for motor ratings had the following population values: a half-life of effect delay of 21 minutes, a concentration at 50% effect of 1.55 mg/L, an E-max of 2.39 U on the treatment response scale, and a sigmoidicity of the E-max function of 11.6. Conclusions: For the typical unmedicated subject, it will take 51.4 minutes until the peak levodopa effect is reached after a bolus dose. This delay is, like the magnitude of the effect, highly variable in this patient group. The residual error magnitudes of 20% for levodopa concentrations and 0.92 U (SD) for motor ratings indicate that the models developed provide predictions of a relevant quality. The developed model may be a first step toward model-guided treatment individualization of duodenal infusion of levodopa.
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| 4. |
- Westin, Jerker, 1971-
(author)
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Decision Support for Treatment of Patients with Advanced Parkinson’s Disease
- 2010
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Doctoral thesis (other academic/artistic)abstract
- The overall aim of this thesis was to develop, deploy and evaluate new IT-based methods for supporting treatment and assessment of treatment of advanced Parkinson’s disease. In this condition a number of different motor and non-motor symptoms occur in episodes of varying frequency, duration and severity. In order to determine outcome of treatment changes, repeated assessments are necessary. Hospitalization for observation is expensive and may not be representative for the situation at home. Paper home diaries have questionable reliability and storage and retrieval of results are problematic. Approaches for monitoring using wearable sensors are unable to address important non-motor symptoms. A test battery system consisting of both self-assessments of symptoms and motor function tests was constructed for a touch screen mobile phone. Tests are performed on several occasions per day during test periods of one week. Data is transmitted over the mobile net to a central server where summaries in different symptom dimensions and an overall test score per patient and test period are calculated. There is a web application that graphically presents the results to treating clinical staff. As part of this work, a novel method for assessment of spiral drawing impairment useful during event-driven sampling was developed. To date, the system has been used by over 100 patients in 10 clinics in Sweden and Italy. Evidence is growing that the test battery is useful, reliable and valid for assessment of symptoms during advanced Parkinson’s disease. Infusion of a levodopa/carbidopa gel into the small intestine has been shown to reduce variation in plasma drug levels and improve clinical response in this patient category. A pharmacokinetic-pharmacodynamic model of this intestinal gel infusion was constructed. Possibly this model can assist the process of individualization of dosage for this treatment through in numero simulations. Results from an exploratory data analysis indicate that severity measures during oral levodopa treatment may be factors to consider when deciding candidates for infusion treatment.
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| 5. |
- Westin, Jerker, 1971-, et al.
(author)
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Outcome prediction of enteral levodopa/carbidopa infusion in advanced Parkinson's disease
- 2006
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In: Parkinsonism & Related Disorders. - : Elsevier BV. - 1353-8020 .- 1873-5126. ; 12:8, s. 509-513
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Journal article (peer-reviewed)abstract
- Two studies comparing intraduodenal infusion of a levodopa/carbidopa gel with oral treatments in advanced PD patients demonstrated improvement in UPDRS scores and in frequent clinical ratings on a global treatment response scale. Further analysis of data from these studies was performed to find predictive factors related to degree of improvement with infusion. Pearson's correlation coefficients between measures of improvement and baseline variables were calculated. Using data from one study, a prediction model was designed and was then evaluated using the other study's data. Correlations were found indicating that patients with more severe symptoms at baseline were most improved after infusion.
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| 6. |
- Westin, Jerker, 1971-, et al.
(author)
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Validation of a home environment test battery for supporting assessments in advanced Parkinson’s disease
- 2012
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In: Neurological Sciences. - Milano : Springer Science and Business Media LLC. - 1590-1874 .- 1590-3478. ; 33:4, s. 831-838
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Journal article (peer-reviewed)abstract
- Test sequences in a test battery for Parkinson's disease patients, consisting of self-assessments and motor tests, were carried out repeatedly in a telemedicine setting, during week-long test periods and results were summarized in an 'overall score'. 35 patients in stable and fluctuating conditions (15 age- and gender-matched pairs) used the test battery for 1 week, and were then assessed with UPDRS and PDQ-39. This procedure was repeated 1 week later, without treatment changes. Reliability was assessed by intraclass correlation coefficients and Cronbach's alpha. Convergent validity was assessed by Spearman rank correlations and known-groups' validity, by the Mann-Whitney test. According to anonymous usability questionnaires, the patients could easily complete the tasks. Median compliance (93%) and test-retest reliability (0.88) were good. The correlations between overall score and total UPDRS (-0.64) and PDQ-39 (-0.72) were adequate. Median overall score was 18% better in the stable compared to the fluctuating group (p = 0.0014).
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