The diagnostic criteria must include two or more of the following

1. Straining during at least 25% of defecations
2. Lumpy or hard stools in at least 25% of defecations
3. Sensation of incomplete evacuation for at least 25% of defecations
4. Sensation of anorectal obstruction/blockage for at least 25% of defecations
5. Manual maneuvers to facilitate at least 25% of defecations (e.g., digital evacuation, support of the pelvic floor)
6. Fewer than three defecations per week 2. Loose stools are rarely present without the use of laxatives 3. Insufficient criteria for irritable bowel syndrome * Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis

This scale includes 39 items assessing the following regions: mobility (10 items), activities of daily living (6 items), emotional well-being (6 items), stigma (4 items), social support (3 items), cognitions (4 items), communications (3 items) and bodily discomfort (3 items). Alternatively, the sum of the scores can assess the overall health-related quality of life profile of the individual questioned. Scores in each region should be added. The score of the answers ranges from 0 to 4 for each item and the total score ranges from 0 to 116, where higher scores reflect worse life quality.

This scale includes 15 items that address eight aspects of sleep disturbances in PD, including overall quality of night's sleep (item 1)), score of item 1 less than 6 is defined as sleep disorder. Score of all the questions will be summed. The score of the answers ranges from 0 to 10 for each item and the total score ranges from 0 to 150, where higher scores reflect better sleep condition.

This scale includes 8 items. Score of all the questions will be summed. All items were rated on a 4-point scale (0-3), with a minimal score of 0, and maximum total score of 24. A higher score demonstrates more severe excessive daytime sleepiness. Participants were classified as showing excessive daytime sleepiness if their total score ≥10 .

This scale includes 13 items. Score of all the questions will be summed. Total score of the answers ranges from 0 to 100, where higher scores reflect severer rapid eye movement sleep behavior disorder.The optimal cutoff value for the overall scale is 17; subjects were classified as showing RBD when they reached the above score.

1. have, or have you had, recurrent uncomfortable feelings or sensations in your legs while you are sitting or lying down
2. have, or have you had, a recurrent need or urge to move your legs while you were sitting or lying down
3. more likely to have these feelings when you are resting
4. If you get up or move around when you have these feelings, these feelings get better
5. these feelings in your legs most likely to occur at mid-day or afternoon or evening or night
6. Simply changing leg position by itself once without continuing to move usually relieve these feelings usually don't relieves
7. These feelings are not or not always due to muscle cramps

This scale includes 30 items. Score of all the questions will be summed. All items were rated on a 2-point scale (0-1), with a minimal score of 0, and maximum total score of 30. A higher score demonstrates more better cognitive condition. The definition of cognitive disorder differs in education level. For illiteracy, presence of cognitive impairment is defined as MMSE score. For those only receive elementary education, the cut-off value is 20. For other patients, presence of cognitive impairment was defined as MMSE scores less than 25.

This scale includes 6 items. Score of all the questions will be summed. All items were rated on a 4-point scale (1-4), with a minimal score of 6, and maximum total score of 24. A higher score demonstrates more worse sense of olfaction. The cutoff value HRS is 22.5.

This scale includes 17 items. Score of all the questions will be summed. Total score ranges from0-53. A higher score demonstrates more severer depression. The study participants were defined to be not depressed (scores 0-6) , to have minor depression(scores 7-14), or to have major depression (scores above 14) at the different visits during follow-up

This scale includes 9 items. Score of all the questions will be summed. All items were rated on a 7-point scale (1-7). Total score ranges from0-63. A higher score demonstrates more severer fatigue.

Parts II and III provides a total summed score between 0 and 28. Part II (items 2-6, scoring range 0-19) rated the severity of FOG based on its duration and frequency in its most common manifestation. Total score will be calculated for comparison.

The presence of dyskinesia is evaluated by the doctor and recordsed.

Total cholesterol ≥6.2mmol/L or low-density lipoprotein ≥4.1mmol/L or triglyceride ≥2.3mmol/L; or self-reported hyperlipidemia diagnosed by physicians, or taking lipid-lowering drugs at baseline.