AGAlexander Gillespie

Alexander Gillespie

*This is an algorithmically generated author record based on publicly available information.

Alexander Gillespie has a total of 19 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Association Between Tremor Severity and Caregiving Intensity in Essential Tremor

    by Margaret E. Gerbasi, Rodger J. Elble, Holly A. Shill, Eddie Jones, Alexander Gillespie, John Jarvis, Elizabeth Chertavian, Zachary Smith, Ludy C. Shih

    Background: Essential tremor (ET) is a common movement disorder that affects the upper limbs in vital activities of daily living. Few studies have examined the impact of tremor severity on caregiving intensity. Methods: Clinic-based data were collected in the United States (US) from March 2021 to August 2021 through the Adelphi ET Disease Specific Programme (DSP). Linked data between physician and care partner/patient pairs were used to evaluate care partner-reported weekly hours of patient care. Tremor severity was assessed with the Essential Tremor Rating Assessment Scale (TETRAS) Performance and Activities of Daily Living subscales. Pearson chi-square, correlation and multivariate regression analyses were conducted to examine the relationships between tremor severity and hours of care partner assistance. Results: A quarter of 960 individuals with ET required care partners. Most care partners were spouses (61%), but other family members or friends also served as care partners. About 23% of care partners reported giving constant care, defined as 112 hours per week or more, while the remainder of care partners reported caregiving time averaging 24.5 hours per week. The probability of needing a care partner was significantly associated with tremor severity, and the association between care partner need and tremor severity was moderate (bivariate r = 0.32–0.37) and not substantially impacted by the inclusion of additional covariates (age, sex, race, comorbidity, relationship with patient, and living with patient). Discussion: Roughly 25% of patients with ET have care partner needs, and the number of care partner hours provided is correlated with tremor severity. Therefore, treatments that ameliorate tremor severity have the potential to reduce caregiving intensity in ET.


  • Open Access

    Work and Activity Impairment in Individuals with Essential Tremor

    by Margaret E. Gerbasi, Rodger J. Elble, Holly A. Shill, Eddie Jones, Alexander Gillespie, John Jarvis, Elizabeth Chertavian, Zachary Smith, Ludy C. Shih

    Background: Essential tremor (ET) affects nearly 7 million people in the United States and consists of upper limb tremor that can affect activities of daily living, including activities related to work. Research examining the effect of ET on work productivity is limited and there are no studies using validated work productivity instruments. Methods: Clinic-based data were collected between March 2021 and August 2021 from US physicians participating in the Adelphi ET Disease Specific Programme (DSP). Patients were evaluated with the Essential Tremor Rating Assessment Scale (TETRAS), Quality of Life in Essential Tremor (QUEST) questionnaire, and the Work Productivity and Activity Impairment (WPAI) questionnaire. Statistical associations between tremor severity and work productivity were examined. Results: A total of 1,003 ET patients were identified, and 420 patients completed the WPAI questionnaire and were included in this study. Activity impairment was independently associated with tremor severity, adjusting for age, full-time vs. part-time employment, household income, depression, and anxiety. Of those who were employed (n = 165), 133 (80.6%) were employed full-time, and 141 (85.5%) had some level of work impairment. Work impairment was also independently associated with tremor severity, adjusting for the same covariates. Among those patients for whom QUEST responses were available, 47% (64/135) of patients with ET working full-time and 88% (36/41) of those working part-time reported that tremor interfered with work. Discussion: Work impairment is significantly correlated with tremor severity. Although a minority of patients in this clinic-based cohort were identified as employed, nearly all reported a negative impact on work performance.


  • Open Access

    Clinical, Humanistic, and Economic Value of ‘Good ON-Time’ in Advanced Parkinson’s Disease: A Multinational Real-World Study

    by Joohi Jimenez-Shahed, Irene A. Malaty, Jean-Philippe Azulay, Ashwini Parab, Connie H. Yan, Prasanna L. Kandukuri, Pavnit Kukreja, Jorge Zamudio, Alexander Gillespie, Angelo Antonini

    Introduction In advanced Parkinson's disease (aPD), ‘ON-time’ indicates periods of better symptom control, with ‘good ON-time (GOT)’ indicating control without troublesome dyskinesia. Despite its importance, the impact of increased ‘GOT’ on aPD outcomes is understudied. This study aims to evaluate the clinical, humanistic, and economic value of incremental hourly increases in ‘GOT’ for people with aPD. Methods The study analyzed data from people with aPD across seven countries, using the Adelphi Parkinson's Disease Specific Program survey (2017–2020). ‘GOT’ (calculated from self-reported ON/OFF-time and the proportion of troublesome dyskinesia time) was normalized to a 16-h day. Outcomes included symptom control, medication use, falls, activities of daily living (ADLs), quality of life (QoL), and healthcare resource utilization (HRU). Regression models evaluated relationships between incremental ‘GOT’ hours and outcomes. Results Of 802 patients (mean [standard deviation; SD] age, 76.1 [8.9] years; male, 60.3%) included in the analysis, mean (SD) ‘GOT’ was 13.1 (2.7) hours/day. Hourly increases in ‘GOT’ were associated with lower likelihood of reporting uncontrolled motor (odds ratio [OR] 0.79; 95% confidence interval (CI) [0.62, 1.01]) and non-motor symptoms (OR 0.88; 95% CI [0.80, 0.96]), taking ≥ 2 PD medication classes (OR 0.91; 95% CI [0.86, 0.97]) and lower fall risk (incidence rate ratio 0.91; 95% CI [0.87, 0.95]). Hourly increases in ‘GOT’ were significantly associated with reduced humanistic burden (greater ADL independence, OR 1.19; 95% CI [1.04 1.37]) and improved QoL (for Parkinson’s Disease Questionnaire [PDQ]-39: coefficient − 1.49; 95% CI [− 2.46, − 0.52]) and with reduced economic burden, with annual total HRU cost-savings of $8602.24 (95% CI − $12,192.70 to $5011.77). Conclusions In this multi-country, real-world study of people with aPD, hourly increases in ‘GOT’ were associated with improved clinical outcomes, greater humanistic value, and reduced economic burden. Interventions that maximize improvement of ‘GOT’ should be considered for people with aPD adequately controlled on current therapy.


  • Open Access

    Associations Among Tremor Amplitude, Activities of Daily Living, and Quality of Life in Patients with Essential Tremor

    by Margaret E. Gerbasi, Rodger J. Elble, Eddie Jones, Alexander Gillespie, John Jarvis, Elizabeth Chertavian, Zachary Smith, Mina Nejati, Ludy C. Shih

    Background: Essential tremor (ET) is a disabling syndrome consisting of tremor, primarily in the upper limbs. We assessed the correlation of The Essential Tremor Rating Assessment Scale (TETRAS) Performance Item 4 ratings of upper limb tremor with the TETRAS activities of daily living (ADL) subscale and with 2 quality of life (QoL) scales. Methods: This noninterventional, cross-sectional, point-in-time survey of neurologists(n = 60), primary care physicians (n = 38), and their patients with ET (n = 1,003) used real-world data collected through the Adelphi ET Disease Specific Programme™. Physician-reported measures (TETRAS Performance Item 4 and TETRAS ADL total) and patient-reported QoL measures (generic EuroQol-5 Dimension 5 Level [EQ-5D-5 L] and ET-specific Quality of Life in Essential Tremor Questionnaire (QUEST)) were assessed with bivariate and multivariable analyses. Sensitivity analyses were also conducted. Results: The bivariate association between TETRAS Performance Item 4 score and TETRAS ADL total score was high (Pearson r = 0.761, P < 0.001). The bivariate associations between TETRAS Performance Item 4 score and EQ-5D-5 L index score (r = –0.410, P < 0.001) and between TETRAS ADL total score and EQ-5D-5 L index score (r = –0.543, P < 0.001) were moderate. The bivariate associations between TETRAS Performance Item 4 score and QUEST total score (r = 0.457, P < 0.001), and between TETRAS ADL total score and QUEST total score (r = 0.630, P < 0.001) were also moderate. These associations were unaltered by the inclusion of covariates. Discussion: This study showed that greater tremor severity (TETRAS Performance Item 4) was positively correlated with ADL impairment (TETRAS ADL) and negatively associated with QoL (EQ-5D-5 L and QUEST). TETRAS Performance Item 4 score is a robust predictor of TETRAS ADL total score, and TETRAS Performance Item 4 and TETRAS ADL total scores were robust predictors of the 2 QoL scales. The results demonstrate the value of TETRAS scores as valid endpoints for future clinical trials. Highlights This real-world study assessed TETRAS scores as predictors of impaired QoL in ET. TETRAS Performance Item 4 and ADL were associated with EQ-5D-5 L and QUEST. TETRAS scores may serve as valid endpoints for future clinical trials.