Screening for parkinson syndrome in a Chinese rural population: Re-examination of a historic questionnaire

Background Standardized screening tools for Parkinson syndrome have not been developed for non-western populations. This study aimed to validate the Copiah County questionnaire (CCQ) as a screening instrument in a Chinese rural population. Methods All participants of a previously reported prevalent study were interviewed using CCQ. The participants who answered yes to at least one item on CCQ were defined as positive. The Parkinson's disease (PD) diagnosis was established using United Kingdom Parkinson's disease Brain Bank Clinical diagnosis criteria (UKPDBBC) and served as a gold standard to determine the sensitivity, specificity, and positive and negative predictive values (PPV, NPV) for the questionnaire. Results Among 16 130 participants, 2872 (17.8%) were screened positive for CCQ and 13 258 negative (82.2%). Among the 697 participants diagnosed as having Parkinson syndrome, 605 were positive for CCQ, and 92 were negative, leading to a sensitivity of 86.8%. Out of the 15 433 non-Parkinson syndrome participants, 13 166 were negative to CCQ, giving a specificity of 85.3%. Among the 2872 participants screened positive, 605 were diagnosed with Parkinson syndrome, and their PPV was 21.1%. For the 13 258 participants screened negative on CCQ, 92 were diagnosed with Parkinson syndrome and 13 166 did not have Parkinson syndrome, leading to a NPV of 99.3%. Conclusions CCQ appeared to have satisfactory statistical parameters to serve as a screening instrument for Parkinson syndrome in this rural Chinese population. Further studies may prove the utility of this short questionnaire in Parkinson syndrome screening among Chinese populations including those residing in rural areas.