Table 4.
Item Prevalence and Decision Tree Results
| # Times in Branch 1 or 2 | ||||
|---|---|---|---|---|
| of 100 Decision Trees | ||||
| Item | Prevalence | Multisite Sample | Chronic Illness Sample | |
| *Fatigue | 93.1 | -- | -- | |
| PEM | *Minimum exercise makes you physically tired | 86.4 | 83 | 5 |
| *Next-day soreness/fatigue after everyday activities | 85.1 | 6 | 85 | |
| Physically drained or sick after mild activity | 83.0 | 16 | 29 | |
| Dead, heavy feeling after starting to exercise | 78.1 | 1 | 12 | |
| Mentally tired after the slightest effort | 76.4 | 2 | 69 | |
| Sleep | *Unrefreshed after you wake up in the morning | 90.7 | 100 | 97 |
| Problems staying asleep | 63.6 | 8 | 2 | |
| Problems falling asleep | 59.8 | 0 | 75 | |
| Need to nap daily | 57.9 | 85 | 6 | |
| Waking up early in the morning (e.g. 3am) | 47.8 | 0 | 6 | |
| Sleeping all day and staying awake all night | 11.6 | 0 | 14 | |
| Pain | *Pain or aching in your muscles | 73.9 | 90 | 35 |
| Pain/stiffness/tenderness in >1 joint | 62.7 | 13 | 6 | |
| Headaches | 49.4 | 7 | 7 | |
| *Bloating | 47.9 | 77 | 28 | |
| Abdomen/Stomach pain | 37.4 | 3 | 76 | |
| Eye pain | 28.6 | 4 | 19 | |
| Chest pain | 18.0 | 0 | 27 | |
| Neurocognitive | * Difficulty paying attention for a long period of time | 80.1 | 82 | 54 |
| * Problems remembering things | 76.3 | 42 | 3 | |
| Only able to focus on one thing at a time | 71.3 | 14 | 29 | |
| Difficulty expressing thoughts | 70.8 | 5 | 0 | |
| Muscle weakness | 67.1 | 12 | 0 | |
| Absent-mindedness or forgetfulness | 66.7 | 5 | 3 | |
| Sensitivity to noise | 65.2 | 1 | 38 | |
| Slowness of thought | 64.2 | 2 | 2 | |
| Sensitivity to bright lights | 57.1 | 0 | 53 | |
| Difficulty understanding things | 48.6 | 0 | 0 | |
| Unable to focus vision and or/attention | 47.7 | 0 | 0 | |
| Muscle twitches | 25.1 | 0 | 18 | |
| Loss of depth perception | 19.7 | 0 | 0 | |
| Autonomic | *Irritable bowel problems | 47.7 | 72 | 51 |
| *Feeling unsteady on your feet, like you might fall | 35.9 | 45 | 3 | |
| Shortness of breath or trouble catching your breath | 35.4 | 24 | 60 | |
| Dizziness or fainting | 33.3 | 23 | 12 | |
| Bladder problems | 30.6 | 18 | 5 | |
| Nausea | 25.0 | 1 | 31 | |
| Irregular heart beats | 23.4 | 0 | 38 | |
| Neuroendocrine | *Cold limbs | 57.3 | 86 | 1 |
| *Feeling hot or cold for no reason | 54.7 | 78 | 6 | |
| Losing or gaining weight without trying | 37.2 | 11 | 1 | |
| Chills or shivers | 35.7 | 4 | 19 | |
| Night sweats | 32.6 | 6 | 0 | |
| Alcohol intolerance | 30.6 | 10 | 90 | |
| Feeling like you have a high temperature | 29.9 | 1 | 1 | |
| Feeling like you have a low temperature | 25.5 | 0 | 81 | |
| No appetite | 18.1 | 0 | 0 | |
| Sweating hands | 10.5 | 0 | 0 | |
| Immune | *Flu-like symptoms | 54.3 | 98 | 100 |
| *Some smells/foods/meds/chemicals make you feel sick | 42.4 | 35 | 78 | |
| Tender/Sore lymph nodes | 32.5 | 3 | 11 | |
| Sore throat | 30.4 | 4 | 9 | |
| Fever | 19.7 | 0 | 2 | |