Medication Responsiveness of Motor Symptoms in a Population-Based Study of Parkinson Disease

We assessed degree of Parkinson disease motor symptom improvement with medication among subjects enrolled in an ongoing, population-based study in Central California. The motor section of the unified Parkinson disease rating scale (UPDRS) was performed on subjects in both OFF and ON medication states, and difference between these scores was used as an indicator of symptomatic benefit. Higher OFF minus ON scores correlated with more severe baseline symptoms. There was equivalent improvement on the motor UPDRS scale for subjects divided according to medication classes used: levodopa alone 7.3 points, levodopa plus other medications 8.5 points, and dopamine agonists but not levodopa 6.1 points. In addition, there was no difference in the magnitude of improvement when subjects were divided according to Parkinson disease subtype, defined as tremor dominant, akinetic-rigid, or mixed. In this community-based sample, these values are within the range of a clinically important difference as defined by previous studies

Using Administrative Databases to Calculate Framingham Scores within a Large Healthcare Organization

Background and Purpose—Framingham calculators are typically implemented in 1-on-1 settings to determine if a patient is at high risk for development of cardiovascular disease in the next 10 years. Because health care administrative datasets are including more clinical information, we explored how well administrative data-derived Framingham scores could identify persons who would have stroke develop in the next year. Methods—Using a nested case-control design, we compared all 313 persons who had a first-time stroke at 5 Veterans Administration Medical Centers with a random sample of 25 361 persons who did not have a first-time stroke in 2008. We compared Framingham scores and risk using administrative data available at the end of 2007. Results—Stroke patients had higher risk profile than controls: older age, higher systolic blood pressure and total cholesterol, more likely to have diabetes, cardiovascular disease, left ventricular hypertrophy, and more likely to use treatment for blood pressure (P<0.05). The mean Framingham generalized cardiovascular disease score (18.0 versus 14.5) as well as the mean Framingham stroke-specific score (13.2 versus 10.2) was higher for stroke cases than controls (both P<0.0001). The c-statistic for the generalized cardiovascular disease score was 0.68 (95% CI, 0.65–0.70) and for the stroke score was 0.64 (95% CI, 0.62–0.67). Conclusions—Persons who had a stroke develop in the next year had a worse Framingham risk profile, as determined by administrative data. Future studies should examine how to improve the stroke predictive tools and to identify the appropriate populations and uses for applying stroke risk predictive tools

Confirmatory Factor Analysis of the Motor Unified Parkinson’s Disease Rating Scale

The motor examination section of the unified Parkinson's disease rating scale (UPDRS) is widely used in research but few studies have examined whether subscales exist that tap relatively distinct motor abnormalities. We analyzed data from 193 persons enrolled in a population-based study in Central California. Patients were examined after overnight PD medication washout (“OFF” state) and approximately one hour after taking medication (“ON” state). We performed confirmatory factor analysis of the UPDRS for OFF and ON state examinations; correlations, reliability, and relative validity of resulting subscales were evaluated. A model with five factors (gait/posture, tremor, rigidity, bradykinesia affecting the left extremities, bradykinesia affecting the right extremities) fit the data well, with similar results for OFF and ON states. Internal consistency reliability coefficients were 0.90 or higher for all subscales. The gait/posture subscale most strongly discriminated across levels of patient reported PD symptom severity and of how PD affects them on a daily basis. Compared to the right sided bradykinesia subscale, the left sided bradykinesia subscale had higher discrimination across levels of self-reported PD symptom severity and functional impairment. This supports motor UPDRS containing multiple subscales that can be analyzed separately and provide information distinct from the total score that may be useful in clinical studies

Development and preliminary evaluation of a quality of life measure targeted at dementia caregivers

<p>Abstract</p> <p>Background</p> <p>Providing care for individuals with a progressive, debilitating condition such as dementia can adversely impact the quality of life (QOL) of informal caregivers. To date, there is no existing caregiver quality of life measure for dementia caregivers with breadth of coverage or that is applicable to caregivers of diverse ethnic backgrounds. The purpose of this study was to develop and evaluate a caregiver-targeted quality-of-life measure (CGQOL) for informal caregivers of persons with dementia that can be used with caregivers from a variety of ethnicities.</p> <p>Methods</p> <p>91 items were field tested by telephone interviews with 179 English-speaking and 21 monolingual Spanish-speaking caregivers of persons with dementia. Repeat interviews were conducted with 71 caregivers. Administration time, scale score distributions, item-scale correlations, reliability, and associations of scales with patient and caregiver demographic and caregiving characteristics were estimated. Structure of associations among scales was examined using exploratory factor analysis.</p> <p>Results</p> <p>Item analysis yielded 80 items distributed across 10 scales, with median administration time of 17 minutes [IQR 13.5–22 minutes] and minimal missing data. There were few floor or ceiling effects in scale score distributions. Internal consistency reliability was ≥ 0.78 for all scales; test-retest reliability (intraclass correlation) estimates exceeded 0.70 for 6 scales. More hours weekly spent in caregiving was uniquely associated with worse quality of life on 8 scales (p's ≤ 0.05). Three higher-order dimensions of caregiving assistance, emotional and social concerns, and spirituality and benefits were identified.</p> <p>Conclusion</p> <p>These preliminary results support subsequent evaluation of test-retest reliability, construct validity, and responsiveness to change of this quality-of-life measure for caregivers from diverse ethnicities.</p

SF-36 includes less Parkinson Disease (PD)-targeted content but is more responsive to change than two PD-targeted health-related quality of life measures

To compare validity including responsiveness, and internal consistency reliability and scaling assumptions of a generic (SF-36) and Parkinson Disease (PD)-targeted (PDQ-39; PDQUALIF) health-related quality of life (HRQOL) measures. Ninety-six PD patients were administered for all HRQOL measures by telephonic interview at baseline and 18 months. Relative efficiency and responsiveness were compared relative to four external criteria (self-ratings of PD’s daily effects, global Quality of Life, PD symptom severity, and a depression screener). We examined whether PD-targeted measures explained unique variance beyond the SF-36 by regressing criterion variables on HRQOL scales/items. Adequacy of PD-targeted measures’ original scaling was explored by item-scale correlations. Relative efficiency estimates were similar for generic and PD-targeted measures across all criteria. Responsiveness analyses showed that the SF-36 yielded large (&gt;0.8) effect sizes (ES) for three of eight scales for each of two criterion variables, compared to only one large ES for any scale in either PD-targeted measure. Adjusted R 2 increased from 14 to 27% in regression models that included PD-targeted items compared to models with only SF-36 scales. Item-scale correlations showed significant cross-loading of items across scales of the PD-targeted measures. SF-36 responsiveness was better than that of two PD-targeted measures, yet those measures had content that significantly explains PD patients’ HRQOL

SF-36 includes less Parkinson Disease (PD)-targeted content but is more responsive to change than two PD-targeted health-related quality of life measures

To compare validity including responsiveness, and internal consistency reliability and scaling assumptions of a generic (SF-36) and Parkinson Disease (PD)-targeted (PDQ-39; PDQUALIF) health-related quality of life (HRQOL) measures. Ninety-six PD patients were administered for all HRQOL measures by telephonic interview at baseline and 18 months. Relative efficiency and responsiveness were compared relative to four external criteria (self-ratings of PD’s daily effects, global Quality of Life, PD symptom severity, and a depression screener). We examined whether PD-targeted measures explained unique variance beyond the SF-36 by regressing criterion variables on HRQOL scales/items. Adequacy of PD-targeted measures’ original scaling was explored by item-scale correlations. Relative efficiency estimates were similar for generic and PD-targeted measures across all criteria. Responsiveness analyses showed that the SF-36 yielded large (&gt;0.8) effect sizes (ES) for three of eight scales for each of two criterion variables, compared to only one large ES for any scale in either PD-targeted measure. Adjusted R 2 increased from 14 to 27% in regression models that included PD-targeted items compared to models with only SF-36 scales. Item-scale correlations showed significant cross-loading of items across scales of the PD-targeted measures. SF-36 responsiveness was better than that of two PD-targeted measures, yet those measures had content that significantly explains PD patients’ HRQOL

Medication responsiveness of motor symptoms in a population-based study of Parkinson disease.

We assessed degree of Parkinson disease motor symptom improvement with medication among subjects enrolled in an ongoing, population-based study in Central California. The motor section of the unified Parkinson disease rating scale (UPDRS) was performed on subjects in both OFF and ON medication states, and difference between these scores was used as an indicator of symptomatic benefit. Higher OFF minus ON scores correlated with more severe baseline symptoms. There was equivalent improvement on the motor UPDRS scale for subjects divided according to medication classes used: levodopa alone 7.3 points, levodopa plus other medications 8.5 points, and dopamine agonists but not levodopa 6.1 points. In addition, there was no difference in the magnitude of improvement when subjects were divided according to Parkinson disease subtype, defined as tremor dominant, akinetic-rigid, or mixed. In this community-based sample, these values are within the range of a clinically important difference as defined by previous studies