The study was conducted in two phases: 1) the adaptation and translation of the Parent Tic Questionnaire (PTQ) into Chinese for children, and 2) the assessment of the psychometric properties of the Chinese version of the PTQ.
Phase 2 - Assessment of the Psychometric Properties
The ethics committees of Children's Hospital of Fudan University approved this study(NO:2021 − 386). All parents and children read and signed appropriate consent and assent forms prior to participation.
To gather data, a suite of questionnaires, including the newly adapted PTQ, was administered to participants during routine outpatient visits. A key aspect of this phase was the evaluation of the test-retest reliability of the Chinese PTQ. For this, a subset of participants was selected through simple random sampling, using random number tables. These participants were reissued the PTQ two weeks following their initial assessment, allowing for an analysis of the questionnaire's consistency over time.
Participants. This study involved 280 children and adolescents diagnosed with tic disorders (including provisional tic disorder, chronic motor/phonic tic disorder, and Tourette syndrome) according to the DSM-5 criteria. Twelve participants who did not complete the PTQ or other scales were excluded, leaving a final sample of 268 patients (213 male; M age = 9.3, SD = 2.82, range = 6–17). Among the respondents, 193 were mothers, 61 were fathers, and 14 were other relatives, including grandparents and aunts (refer to Table 1 for detailed demographics). All participants were recruited from the Department of Psychological Medicine at Children's Hospital of Fudan University in Shanghai between October 1st, 2021, and December 31st, 2022.
Table 1
Demographic Profile of Respondents of the PTQ
|
Number
|
Percentage
|
Respondent
|
|
|
Father
|
61
|
22.76%
|
Mother
|
193
|
72.01%
|
Others(including grandparents or aunt)
|
14
|
5.23%
|
Education Level of Father
|
|
|
Less than High School
|
47
|
17.54%
|
High school or technical secondary school
|
39
|
14.55%
|
Junior College
|
63
|
23.51%
|
Undergraduate degree
|
89
|
33.21%
|
Postgraduate degree and above
|
30
|
11.19%
|
Education Level of Mother
|
|
|
Less than High School
|
39
|
14.55%
|
High school or technical secondary school
|
46
|
17.16%
|
Junior College
|
60
|
22.39%
|
Undergraduate degree
|
105
|
39.18%
|
Postgraduate degree and above
|
18
|
6.72%
|
Study variables and instruments. The Chinese version of the PTQ[6], Yale Global Tic Severity Scale (YGTSS)[4], Children’s Yale-Brown Obsessive Compulsive Scale (CY-BOCS)[10], Conners’ Parent Rating Scale (CPRS-48)[11] were administered.
As described before, the PTQ is a parent-report measure used to assess the severity of their child's tics. The PTQ measures the frequency and intensity of each tic and provides severity scores for motor tics, vocal tics, and a combined total tic score. The motor tic and vocal tic scores each can go up to 112, and the total score can range from 0 to 224[6].
The YGTSS is a semi-structured clinician-administered interview designed to evaluate the severity of motor and vocal tics over the previous week. The interview assesses the number, frequency, intensity, complexity, and interference of motor and vocal tics. The YGTSS yields total motor and phonic tic scores (ranging from 0–25) that are combined to produce a total tic score (ranging from 0–50). The YGTSS also has a tic impairment rating scored from 0–50[4]. For the purposes of the present investigation, only the total tic score was included in the analyses.
The CY-BOCS is a modified version of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) tailored for use in children. It is a clinician-rated, semi-structured tool that evaluates the severity of obsessions and compulsions. The CY-BOCS includes five items assessing obsessive symptoms and five assessing compulsive symptoms, each scored on a five-point ordinal scale ranging from 0 (none) to 4 (extreme). The total severity score is calculated by summing the scores of all items, with a range of 0 to 40. The instrument has been shown to be reliable and valid for use in children with OCD with substantial evidence from various countries[10].
The CPRS-48 is a parent-report scale commonly used to assess ADHD symptoms and related emotional and behavioral issues in children. The CPRS-48 scale is comprised of 48 questions. In the Chinese version of CPRS-48, the homogeneity reliability of Cronbach α was 0.93, the correlation of Spearman-brown split-half was 0.90, and the retest reliability of the total score was 0.59[11]. Parents answer each question using a 4-point scale ranging from 0 ("not at all true") to 3 ("very much true"), with a higher score indicating more severe behavioral problems. The revised version of the CPRS-48 employs six subscales to evaluate various behavioral outcomes: conduct problems, learning problems, psychosomatic problems, impulsive-hyperactive, anxiety, and ADHD[11].
Data analysis
Statistical analysis was performed using SPSS software (Version 24.0, SPSS Inc., Chicago, IL, USA).
To assess the validity and reliability of the Chinese version of the PTQ, several statistical analyses were conducted. Cronbach’s alphas were conducted to test the internal consistency of the motor tic scale, vocal tic scale, and total tic scale, α values ≥ 0.90 were considered excellent, 0.70 to 0.89 were considered good, 0.60 to 0.69 were considered acceptable, and < 0.60 poor[12]. Test-retest reliability was determined using one way random effects ICCs[13] based on data from 31 participants who completed the retest after two weeks. ICC of 0.75 to 1.00 was indicative of excellent test-retest reliability, values of 0.60 to 0.74 signified good reliability, coefficients ranging from 0.40 to 0.59 indicated poor agreement, and < 0.40 was considered poor[14]. Correlations were calculated between PTQ subscales and total scores and YGTSS subscales and total scores to test concurrent validity. A correlation value of > 0.50 between the PTQ and YGTSS indicated good concurrent validity. Correlations of 0.30 to 0.49 and 0.10 to 0.29 represented fair and poor concurrent validity, respectively[14]. Discriminant validity was evaluated by conducting correlations between PTQ total scores and scores on the CY-BOCS and CPRS-48 subscales. Good discriminant validity was represented by correlations of 0.10 to 0.29 between the PTQ and CY-BOCS, CPRS-48 subscales. Correlation values that exceeded this range were considered fair (0.30 to 0.49) and poor (> 0.50) discriminant validity[14].