A systematic review and economic model of the effectiveness and ...

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Clinical effectiveness
TABLE 32 DEX high dose (>20 mg/day) versus placebo
Study Design Intervention – N Age Duration Core outcomes
(years) (weeks)
Administered once daily
Arnold, 1976 36 C (3×) DEX (mean 21.75 mg/day, 4.6–12 12 Core: Parents’ Behaviour
o.d.?) – 31 Checklist: hyperactivity; Conners’
Teachers’ Behaviour Checklist:
hyperactivity
QoL: global ratings (clinicians)
AE: Parents’ Behaviour Checklist:
somatic complaints; Conners’
Teachers’ Behaviour Checklist:
lack of health; weight
Conrad, 1971 47 P DEX (10–20 mg/day, o.d.?) – 17 4–6 4–6 months Core: no hyp; behaviour ratings
(teacher and parent)
QoL: not reported
AE: not reported
Administered two or more times daily
Greenberg, P DEX (mean 25 mg/day, b.d.) – 17 6.5–11 8 Core: not reported
1972 58 QoL: not reported
AE: incidence of side-effects
C, crossover trial (number of crossovers); P, parallel trial.
Quality of life
Conners and colleagues 45 evaluated Clinical
Global Improvement as measured by a clinician.
The authors reported that after 8 weeks, 33% were
much improved in the DEX group compared with
9% in the placebo group.
Adverse events
No significant differences in the incidence of
headache, loss of appetite, stomach ache or
insomnia were detected between participants of
the trial adequately reporting these outcomes. 56
Data on weight were not reported separately for
those on DEX versus those on placebo.
Summary
One study presented reproducible results for
hyperactivity. 45 In this study, the results were
significant when assessed using the symptom
checklist, but not when assessed using the parent
questionnaire. This study also reported on Clinical
Global Improvement, and reported that children
in the DEX group were more often improved
compared with the placebo group. No significant
differences in the incidence of headache, loss of
appetite, stomach ache or insomnia were reported
in the one study that presented data on these
adverse events. 56 The studies did not score very
well in the quality assessment, and the results
should be interpreted with caution.
DEX high dose (>20 mg/day) versus placebo
Three studies evaluated high dose (>20 mg/day)
DEX compared with placebo (Table 32; with
additional information in Appendix 12). Of these,
two appeared to have examined DEX
administered once daily and one examined DEX
administered twice per day.
Only one of the studies evaluated hyperactivity as
a core outcome, using a number of different
scales. 36 In this study, children in the DEX group
had consistently better scores than children in the
placebo group; however, the authors did not
report results for any statistical comparisons (see
Table 33). Another study reported on behaviour
ratings as assessed by teachers and parents 47 (see
Appendix 12) and the final study reported only on
adverse events (discussed separately below). 58
Quality of life
Arnold and colleagues 36 reported on global
ratings as assessed by clinicians. They reported
that children in the DEX group rated better than
those in the placebo group (p < 0.01).
Adverse events
Of the three trials comparing a high dose of DEX
with placebo, one reported adequate data for the
analysis of adverse events. 58 In this trial,
participants assigned to DEX suffered from loss of