The Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing data
Background: the Parkinson's Disease Questionnaire (PDQ-39) is the most widely used Parkinson's specific measure of health status. It is increasingly used in treatment trials, sometimes as a primary end-point, where any missing data can potentially cause difficulties in analyses. Objectives...
| Những tác giả chính: | , , , |
|---|---|
| Tác giả khác: | |
| Định dạng: | Journal article |
| Ngôn ngữ: | English |
| Được phát hành: |
Oxford University Press
2006
|
| Những chủ đề: |
| _version_ | 1826264468902903808 |
|---|---|
| author | Jenkinson, C Heffernan, C Doll, H Fitzpatrick, R |
| author2 | British Geriatrics Society |
| author_facet | British Geriatrics Society Jenkinson, C Heffernan, C Doll, H Fitzpatrick, R |
| author_sort | Jenkinson, C |
| collection | OXFORD |
| description | Background: the Parkinson's Disease Questionnaire (PDQ-39) is the most widely used Parkinson's specific measure of health status. It is increasingly used in treatment trials, sometimes as a primary end-point, where any missing data can potentially cause difficulties in analyses. Objectives: the purpose of this article is to evaluate the Expectation Maximisation (EM) algorithm for the imputation of missing dimension scores on the 39-item PDQ-39. Methods: a postal survey of patients diagnosed with Parkinson's disease (PD). A total of 1,372 patients were surveyed and 839 (61.15%) questionnaires returned completed or partially completed. Of these, complete PDQ data were available in 715 (85.22%) cases. Data were deleted from this complete dataset and a sub-set of 200 respondents from this dataset and then imputed using the EM algorithm; results were then compared to the dataset before data deletion. Results: results gained from imputation of data closely mirrored that of the complete dataset in each case. Descriptive statistics, mean scores and spread of scores were almost identical between original and imputed datasets. Furthermore, original and imputed datasets were highly correlated [intra-class correlation coefficient (ICC) = 0.93 or greater], and mean differences were small (±1.00). Conclusions: the results suggest that the use of EM for the PDQ-39 provides data that closely mirrors the original when this has been deliberately removed. Consequently, EM is likely to be appropriate for trials using the PDQ that contains missing data points. |
| first_indexed | 2024-03-06T20:08:18Z |
| format | Journal article |
| id | oxford-uuid:29a9dcf8-f552-4e15-844c-184bc7708b58 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:08:18Z |
| publishDate | 2006 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:29a9dcf8-f552-4e15-844c-184bc7708b582022-03-26T12:20:30ZThe Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing dataJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:29a9dcf8-f552-4e15-844c-184bc7708b58Public HealthEnglishOxford University Research Archive - ValetOxford University Press2006Jenkinson, CHeffernan, CDoll, HFitzpatrick, RBritish Geriatrics SocietyBackground: the Parkinson's Disease Questionnaire (PDQ-39) is the most widely used Parkinson's specific measure of health status. It is increasingly used in treatment trials, sometimes as a primary end-point, where any missing data can potentially cause difficulties in analyses. Objectives: the purpose of this article is to evaluate the Expectation Maximisation (EM) algorithm for the imputation of missing dimension scores on the 39-item PDQ-39. Methods: a postal survey of patients diagnosed with Parkinson's disease (PD). A total of 1,372 patients were surveyed and 839 (61.15%) questionnaires returned completed or partially completed. Of these, complete PDQ data were available in 715 (85.22%) cases. Data were deleted from this complete dataset and a sub-set of 200 respondents from this dataset and then imputed using the EM algorithm; results were then compared to the dataset before data deletion. Results: results gained from imputation of data closely mirrored that of the complete dataset in each case. Descriptive statistics, mean scores and spread of scores were almost identical between original and imputed datasets. Furthermore, original and imputed datasets were highly correlated [intra-class correlation coefficient (ICC) = 0.93 or greater], and mean differences were small (±1.00). Conclusions: the results suggest that the use of EM for the PDQ-39 provides data that closely mirrors the original when this has been deliberately removed. Consequently, EM is likely to be appropriate for trials using the PDQ that contains missing data points. |
| spellingShingle | Public Health Jenkinson, C Heffernan, C Doll, H Fitzpatrick, R The Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing data |
| title | The Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing data |
| title_full | The Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing data |
| title_fullStr | The Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing data |
| title_full_unstemmed | The Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing data |
| title_short | The Parkinson's Disease Questionnaire (PDQ-39): evidence for a method of imputing missing data |
| title_sort | parkinson s disease questionnaire pdq 39 evidence for a method of imputing missing data |
| topic | Public Health |
| work_keys_str_mv | AT jenkinsonc theparkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata AT heffernanc theparkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata AT dollh theparkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata AT fitzpatrickr theparkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata AT jenkinsonc parkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata AT heffernanc parkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata AT dollh parkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata AT fitzpatrickr parkinsonsdiseasequestionnairepdq39evidenceforamethodofimputingmissingdata |