Cognitive Function and Addiction Under Opioid Tapering

EKHO, computer program that registers the continuous reaction time to respond to the emission of a sound signal. Scores were summarized in milliseconds using 10th (fastest values), 50th and 90th (slowest values) percentiles. More prolonged times mean worse performance.

Finger Tapping Test, a mechanical device with a key attached was used to record the number of taps. Score was calculated by the numbers of taps, considering the average of each hand and the differences between hands. Higher scores mean better performance.

Digit Span Test, subjects should repeat orally series of numbers of increasing lengths, in forward and backward orders. Scores were calculated separately for forward and backward exercises, considering the number of correct repetitions. Scores range from 0 to 14. Higher scores mean better performance.

Trail Making Test B, numbers and letters written on a paper should be connected in alternated sequence and increasing order. Score was calculated by the total time spent to correctly conclude the test (seconds). Shorter time mean better performance.

Mini Mental State Examination, measures orientation to time and place, registration of words, attention, calculation, and word recall, as well as language and visual construction. Total scores range from 0 to 30; scores below 27 were considered indicative of cognitive dysfunction.

Pain Medication Questionnaire, 26 items responded on a 5-point Likert format scale. Scores range from 0 to 104, higher score means higher risk of opioid misuse. Scores equal or above 22 were considered indicative of risk for opioid addiction.

Verbal numerical scale from 0=no pain to 10= worst pain, to assess pain right now and average pain.

Number of total hours of sleep in the previous night before assessment

Rest sensation assessed by the question "do you feel rested?". Answers were categorized as yes or no.

RAND 36-Item Short Form Health Survey version 1.0., 36 items distributed in 8 scales: physical functioning, bodily pain, role limitations due to physical health, role limitations due to emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions. Each item was scored on a 0 to 100 range. Items in the same scale were averaged together to create the 8 scale scores. A high score defines a more favorable health state.

Hospital Anxiety and Depression Scale, self-assessment about the last week. It has 14 items divided in anxiety subscale and depression subscale with seven items each one.The maximum score for each scale is 21; cut-off scores for each scale were 8 to 10 for possible and 11 or higher for probable presence of mood disorder.

A clinical judgment was also done by the pain specialist physician (possible answers were yes or no)

Objective Opiate Withdrawal Scale, 13 physically observable signs, rated present or absent that reflected common motoric and autonomic manifestations of opiate withdrawal: yawning, rhinorrhea, piloerection, perspiration, lacrimation, mydriasis, hands tremors, hot and cold flashes (shivering), restlessness (frequent shifts of position), vomiting. muscle twitches, abdominal cramps, and anxiety. Scores range from 0 to 13, higher scores mean more opioid withdrawal symptoms.

Subjective Opiate Withdrawal Scale, self-assessment, 16 items: motoric, autonomic, gastrointestinal, and musculoskeletal opiate withdrawal symptoms and indirectly related psychological symptoms, like anxiety and craving. Answers are scored from 0 to 4 based on how patient is feeling at the time of assessment. Scores range is 0-64, higher scores mean more opioid withdrawal symptoms.

Classification according to Portnoy's Criteria (psychological dependence, evidence of compulsive drug use, and evidence of a group of associated behaviors). Subjects were classified in addict and non-addict.

Diagnostic criteria according to the International Classification of Diseases -10. Subjects should present at least three symptoms associated with addiction in the least month or several times within a year to be considered addict.