Research Methods
Internet-based survey
Surveys are patient-centered and inexpensive to administer and because study participants enter the data directly, there are fewer data entry errors. After individuals with parkinsonism read the consent form, they completed an online survey. The survey takes about an hour to complete and covers information about diet, exercise, sleep, symptoms, medicines, providers, pets, prayer, friends, income, ... we're looking for the secret to success!
IRB Approval
This study was approved by the Bastyr University IRB
(#11A-1301)
ClinicalTrials.gov Identifier: NCT02194816
Published Methodology
The research methods employed here are identical to those described in the prior publication, "Diet & Nutritional Supplements in PD Progression" (Mischley LK, et al., 2017).
For this cross-sectional analysis, only baseline data from individuals with a self-reported diagnosis of idiopathic PD were used. PD severity is defined by the cumulative PRO-PD score, and PD progression is defined by the PRO-PD score adjusted for years since diagnosis. A food frequency questionnaire (FFQ) was developed to quantify dietary intake. The FFQ used in this study was created to be pragmatic and meet the needs of this study by drawing on limitations and successes of other nutritional intake questionnaires. Participants were asked to estimate their intake of foods, on average, over the prior six months. For all dietary variables, participants were given 10 options for rating consumption frequency, ranging from “never” to “5-6 times daily.” Other variables chosen were based on incidence data as well as on biological and clinical relevance. Participants were directed to “Please mark the box if you have taken any of the following consistently over the past 6 months” as well as to identify lifestyle choices that they had been engaged in consistently for the last 6 months. All supplement and behavior variables were recorded as binary variables as people either reported using specific supplements/lifestyles or did not.
Multiple linear and logistic regression models were used to examine the association between diet, lifestyle factors, and PD severity, with PRO-PD scores used as the outcome variable. Food frequency questionnaire data is ordinal; due to the relatively large number (10) of consumption frequencies that were offered as options, it was analyzed as a continuous variable. All models controlled for factors known to heavily influence PD severity including age, years since diagnosis, income and gender. Participant records were excluded if age, years since diagnosis, income, and/or gender data was missing. For participants who did not score an element from the 33 individual PRO-PD symptoms, the cohort average for that individual symptom was substituted for any missing value. All statistical work was done using STATA Version 14 (College Station, TX) with alpha set to 0.05. No adjustments were made for multiple comparisons to avoid increasing the risk of type II errors, and the failure to detect an association that is present was a priority for this observational study.
Outcome Measures
“Complementary and Alternative Medicine in PD" (CAM Care in PD)
CAM Care in PD is a pragmatic, prospective observational study that was designed to describe modifiable lifestyle variables associated with patient-reported symptoms of parkinsonism. Recruitment occurred via social media, IRB-approved recruitment cards distributed at PD support groups and at neurology conferences. A study webpage, hosted by Bastyr University, provided automated access to participation.