Study design
This multicentre randomized controlled (RCT) study was conducted on children aged 9–15 years with ADHD in Sweden. It was designed as a randomized study following the CONSORT statements [46] with an intervention group and a control group with different extents of treatment [47]. In this study, the control group was offered only one of the three interventions offered to the intervention group.
Before conducting an RCT study, it is recommended that the design, data collection and intervention should be investigated in a real-world setting to make it possible to make any changes needed [47]. A pilot study was, therefore, conducted with five children with ADHD aged 9–15 years. The purpose of the pilot study was to test if the data collection and the content and length of the intervention were feasible and acceptable for the participants. The results indicated the feasibility, based on parent’s, children’s, coaches’ and occupational therapists’ evaluations.
The intervention was designed to be multimodal, based on guidelines for interventions for children and adolescents with ADHD [10, 24] and had three components: advocacy, compensation, and remediation [48]. Both groups were exposed to advocacy in the form of education for parents and coaches. The education was given for three reasons: first, as a basis for parents and coaches to increase their understanding of deficits in the child’s TPA and how this could affect the child’s DTM; second, to motivate the parents and coaches to facilitate the participation of the child in the intervention; and third, for ethical reasons to offer at least some form of intervention to all children.
Subsequently, the intervention group received the additional two components: compensation and remediation. The compensation component consisted of working around the problem using different types of TAD, finding individual compensation strategies and structuring the physical environment [48], all according to every child’s needs.
In the remediation component, the children were supported in training time skills by a coach. This intervention component was based on work from Langberg et al. [25, 31] with coaches supporting the child to learn organizational skills. Training with a coach was chosen to make it easier for the child to perform the training often, regularly and in an everyday environment at school or at home.
Data collection was done at baseline (t1), both for the intervention and the control group. The intervention lasted for 12 weeks. The choice of the length of intervention period was based on clinical experience and previous studies training OTMP [7, 20]. Then there was an implementation phase of another 12 weeks, when neither of the groups received any treatment beside standard methods of care, i.e. medication and/or psychological support. After 24 weeks, there was a follow-up assessment (t2). This study design was chosen based on clinical knowledge that starting to use an assistive device takes some time to be integrated with the person’s everyday life [49, 50]. As regards the control group, in addition to the education day, the child and family were only offered standard methods of care (see Fig. 1). After 24 weeks, the children in the control group were offered interventions (data not shown).
Study population and recruitment
Participants were recruited from three child and adolescent psychiatric clinics (CAPs) and one children’s habilitation service (HAB) in Sweden between September 2012 and March 2015. The clinics represented large cities, small towns and sparsely populated areas. All the children had had a steady prescription of ADHD medication for at least 3 months, and were evaluated by their physician or the first author (BW) for inclusion in the study.
Inclusion criteria were a diagnosis of ADHD, age 9–15 years and parent-reported difficulties with DTM, despite medication for ADHD and ten points or more on a clinical rating of 15 statements related to problems with DTM. The statements were chosen from the subscales “Planning and organizing”, “Time concepts” and “Coping in learning” of the questionnaire “Five to Fifteen” (FTF) [51] made by the physician or the first author (BW) together with the parents. Examples of statements were if the child was stressed by time limits, had difficulties in using a watch or being on time for an appointment, or if the child was “lost in his/her own world” and was not aware of the passage of time. Further examples were when a child had obvious difficulties in carrying out and completing morning chores and arriving in time for school, had difficulties in calculating the time span for daily activities and leisure activities, or forgot booked appointments. Parents judged the child’s problems by rating the statements “not correct” (0p), “sometimes correct” (1p) or “correct” (2p). The exclusion criteria were autism spectrum disorder, ID (IQ < 70), or language barriers (e.g. not being able to answer questionnaires in Swedish).
Parents of the children with ADHD who met the above criteria were asked to participate in the study during normal monitoring visits to the CAPs or HAB. Information about the study’s purpose and structure was provided orally, and in writing in the form of a booklet with brief information. Parents were also asked to enrol a person (preferably a teacher or another member of the school staff) to function as the child’s coach. Parents who agreed to participate received written invitations for a personal visit for the purpose of data collection, one invitation for the parents and an adapted version for the child, accompanied by a consent form.
Procedure and intervention
Baseline data collection (t1) took place at the outpatient clinic in the course of two visits (in less than one-third of the cases only in one visit). The number of visits was based on the occupational therapist’s knowledge of the child’s ability to cope and travelling time to the outpatient clinic. Written informed consents were collected from both parents (and older children), before or at the start of the first visit. At the first visit information was given to the child and the parents about the study and the randomization process. Data collection was carried out with the child and the parent separately.
During the visit/visits, the parents met a trained occupational therapist for an interview to identify and prioritize everyday issues that restricted or impacted the child’s performance in everyday living, and to respond to the Time-Parent scale questionnaire. They then met with an assistant to respond to demographic questions. The child met a research assistant/the first author to respond to a questionnaire (data are not used in the present study) and the trained occupational therapist for an assessment (KaTid), and to respond to the self-rating questionnaire Time-Self-rating. If needed, the child was offered help by reading or explaining the questions in the self-rating questionnaires.
Interventions were consistently scheduled to occur twice a year. When a group of children (usually four or six in the same local area) with informed consent were enrolled, and baseline data collection were completed, parents and coaches received a (1-day) manualized education session. The last author generated a randomization list matched for age and sex in accordance with random.com and the children were randomized 1:1 for intervention or control groups. Information about assignment to intervention or control groups was given to the parents at the end of the education session (see Fig. 1).
The education lasted for 6 h and was given in groups. Each child’s parents and coach were invited to participate, along with additional school staff if they wanted to. The education included group discussions, exchanging experiences and discussing strategies. The focus was on lectures about DTM and the development of TPA in typically developing children as compared with children with ADHD. It also contained information about the consequences of TPA deficiencies in daily activities and how to find strategies to compensate for these consequences and how to support children with deficiencies in time-related skills. The instruction was manualized and GJ was responsible for the content and conducted all sessions.
The additional intervention for the intervention group (compensation and remediation) lasted for about 12 weeks, with treatment sessions provided by an occupational therapist and a coach supporting the child. The occupational therapist met the child and parent(s) to give feedback about the assessment findings. In this meeting, the occupational therapist, the parent(s) and the child identified and decided on one to three goals, and made an individualised plan for the compensation intervention. The occupational therapist also met the coach and the parents separately to give feedback on the assessment findings and to give instructions for the training.
The first component, compensation, included three or four treatment sessions (lasting for about 1½ h), with both parents and the child participating. The focus was on finding compensating strategies for the child, structuring the physical environment, and prescribing TAD. The intervention was tailored to the individual needs of the child [16, 41, 48]. Examples of compensating strategies could be to establish and maintain functional morning and evening routines and spreading homework over smaller units of time. Examples of structuring the physical environment could be to organize clothes and sportswear so that they were easy to find and to make sure there were clocks visible in all rooms at home. Prescribing of TADs included choosing an adequate TAD and introduction of the TAD, and later follow-up on the use of TAD.
In the second component of the intervention, remediation, in which the child performed time-skill training, the child was supported by a coach. The time-skill training was in the form of “challenging tasks”. The concept of challenging tasks was inspired by “My Time” (in Swedish Min Tid), a program designed for children with ID. In the present study, the challenging tasks were specially developed for children and adolescents with ADHD (by GJ and BW). The challenging tasks consisted of 14 tasks of increasing complexity, starting with collecting experiences of time duration, followed by training in time orientation and later on in time management. An example of a task in time perception was to measure, in minutes, the duration of five self-chosen recurrent activities and document in a binder. Another example was to compare the amount of time needed to perform the same activity in two different ways, e.g. to walk to school or to bike to school. One example of a task training time orientation was to use a computer program to learn to tell the time. In training time management, the child used the self-measured activities and decided how many of them could be fitted into a 45-min period. Another example was to document school activities in a calendar and to check the calendar every day. All the challenging tasks were gathered in the binder, together with instructions on how to perform the tasks. Every child was supposed to complete ten different tasks. Four out of the 14 tasks were exchangeable, depending on the age and maturity of the child. The child was supposed to do the challenging tasks for 20 min/day and was supported by the coach in a short meeting one to three times/week during the training period.
All coaches who supported the child were offered supervision by an occupational therapist at two sessions during the training period, as a group session or an individual session by telephone. At these meetings the challenges and the way to support the child could be discussed.
The occupational therapists responsible for the intervention had experience of working with children with disabilities and time difficulties. All of them were certified KaTid raters before entering the study. KaTid certification includes a 3-day course for professionals, complemented with homework and a number of KaTid assessments of children with and without disabilities. The occupational therapists in the present study also participated in the education day, along with the parents and coaches.
Treatment integrity
Treatment integrity was controlled for in the following ways. The content of the education day was manualized and also the time-skill training. The coaches and the occupational therapists documented when and what was done in every training session and in meetings with the parents, in a special protocol. During the study, the occupational therapists were invited to attend recurrent days of seminars in groups to discuss interventions and to ensure that the same setup was used. They were also offered individual support by GJ and BW, via telephone or e-mail, if needed.
Subjects
The ADHD diagnosis was determined in accordance with DSM-IV criteria by an experienced CAP clinician after a thorough neuropsychological investigation encompassing careful clinical examination, and monitored with the help of both questionnaires and, in most cases (> 90%), a computer-based assessment of core symptoms of ADHD: QbTest (Qbtech. Quantitative behaviour technology. https://www.qbtech.com/. Accessed 13 Jan 2017).
The parents of 65 children (46 boys, 19 girls) were asked to participate. The mean age at inclusion was 11.6 years (range 8.6–16.1, SD 1.90). Written informed consent was received for 46 (71%) children (32 boys, 14 girls), and they were randomly allocated to the intervention/control group. Of these, eight (17%) did not complete the follow-up assessment after 24 weeks, or withdrew their consent or were excluded from analysis (in one case) because of administrative problems. This resulted in 19 children each in the intervention and control groups, respectively, who were evaluated. The number of girls was 10 (26%), five in each group. There were no significant differences between the 38 completers and the eight dropouts concerning age, sex, time measures (see below) on intake ratings.
The flowchart (Fig. 2) presents the allocation of participants, attrition, and remaining participants in the analysis.
Instruments
The Kit for assessing time-processing ability (KaTid) [3] is an instrument for assessment of time perception, time orientation and time management for children of a developmental age of 5–10 years (KaTid-Child) and adolescents with a developmental age of 10–17 years (KaTid-Youth). Time perception in KaTid is comparable with the ICF-CY:s code b1802, experience of time, including knowing the duration of activities. Time orientation and time management is comparable with the codes b1140 and b1642 in the ICF-CY. The child responds to questions and performs practical exercises, such as setting a timer for a fixed time and placing picture sequences in the correct order. This instrument is interdisciplinary and the testing is performed by a trained professional person, e.g. an occupational therapist. KaTid-Child contains 57 items measuring time perception (15 items), time orientation (32 items) and time management (10 items), summarized into one measure of TPA. KaTid-Youth contains the same sub-groups, but consists of 59 items, 33 of which are the same as in KaTid-Child. KaTid-Child and KaTid-Youth have been shown to have good validity and reliability with children and adolescents, with and without disabilities, in measuring the same construct and measuring change [3, 41]. KaTid-Child has been validated and tested for internal consistency in children with and without disabilities—the Cronbach alpha was 0.78–0.86 [2, 52]. In this study, KaTid-Youth version 19 was used for children from 10 years of age and KaTid-Child version 18b for the youngest children. The same version was used for each child at baseline and at follow-up.
In the Time-Parent scale questionnaire [2], the parents judge their children’s DTM. The questionnaire consists of 12 statements rated on a Likert agreement scale with five response options scored from “do not know” (0p), “never” (1p) to “always” (4p). The Time-Parent scale has been validated and tested for internal consistency, for children and adolescents with and without disabilities, with a Cronbach alpha of 0.79–0.86 [2, 52].
The Time-Self-rating instrument is designed to capture children’s own experience of DTM [53]. It contains 21 statements concerning DTM and 7 items concerning strategies, and has a Likert scale with 4 response alternatives in frequency, scored from “never” (1p) to “always” (4p). The instrument is validated in children aged 10–17 (n = 83) with disabilities using Rasch analysis. The results indicate that 21 items of the Time-Self-rating fitted into a unitary construct measuring DTM, reliability was high (0.82) yielding a separation value of 2.15, altogether good psychometric properties [53]. In the present study, the 21 items measuring DTM were employed.
Statistical analysis
For the KaTid instrument, raw scores were used both as a total score of TPA and for each subscale: time perception, time orientation, and time management.
Sample size was based on findings from an RCT study, [41] including children with disabilities aged 6–11. The intervention group (n = 17) had an average increase of 0.9 logits and the control (n = 20) increased by 0.35 logits (SD: 0.59) in Time-Parent scale during intervention. A power analysis with an independent t test with equal variance showed that a group of 40 children with 80% certainty can discern an increase of 10% at the 5% level.
Demographics were analysed with descriptive statistics. Preliminary analysis with a Shapiro–Wilk’s test [54] confirmed whether the assumptions of normality held for the different variables.
On the basis that there were only two measurement points we used a per-protocol analysis to evaluate the effectiveness of the 12-week intervention, followed by a 12-week implementation period. A change score was calculated for KaTid (sum and on each subscale), for the Time-Parent scale and for the Time-Self-rating. This was done by subtracting the baseline score (t1) for each child from the score at the 24-week follow-up (t2). ANCOVA was used with the difference score as the dependent variable; group, sex and living situation as fixed factors and age as a co-variate. Effect size (ES) was used to analyse the magnitude of the differences in TPA (assessed with KaTid) and in DTM (rated by parents with the Time-Parent scale and by children with the Time-Self-rating) between the control and intervention groups at the 24-week follow-up. It was calculated using Cohen’s d with ES d = 0.2–0.5 representing a small effect, d = 0.5–0.8 medium and d = 0.8 large effect [55].
To evaluate if there were any differences between the sample analysed and the sample lost at follow-up a sensitivity analysis was conducted. Missing data were imputed for the KaTid total score, the subscales time perception, time orientation and time management, as well as the Time-Parent scale and the Time-Self-rating scale, assuming that the difference between intake and 24-week follow-up would be 0 for the dropouts in both the intervention and control groups.
The data were analysed using the Statistic Package for Social Sciences (SPSS) version 24.0 (SPSS Inc. Chicago, IL, USA), selecting a significance level of 0.05 and a confidence interval of 95%.