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

The same method for synthesising the clinicianrated
response rates can be used to estimate the
relationship between response defined on a
clinician-rated scale and response defined on a
parent-rated scale. This allows us to overcome the
lack of parent-rated response rate data for ER-
MPH8 and DEX. As highlighted in the section
‘Clinical effectiveness’ (p. 103), a group of six
trials reported response defined as a reduction of
≥ 25% on the parent-rated ADHD-RS. Three of
the six trials also reported response defined as a
score of 1 or 2 on CGI-S, and one reported
response defined as a score of 1 or 2 on CGI-I.
The additional data provided on this new
definition of response is shown in Table 100.
The trials reported by Spencer and colleagues 89
recruited patients aged between 7 and 13 years,
using DSM-IV diagnostic criteria in a US setting.
At this stage, we can also incorporate the results of
the MTA trial, 133 but only by assuming that the
medical management group in that trial
represents treatment with IR-MPH. The review in
Chapter 4 highlighted that although the majority
of the medication in the MTA trial was IR-MPH, a
proportion consisted of other medications. The
definition of response in the MTA trial was a score
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Health Technology Assessment 2006; Vol. 10: No. 23
TABLE 99 Response rates estimated in extended MTC model in WinBUGS: response defined as score of 1 or 2 on CGI-I or CGI-S
Treatment Response rate, CGI-I baseline (SD) Response rate, CGI-S baseline (SD)
Placebo 0.36 (0.09) 0.15 (0.09)
IR-MPH 0.76 (0.14) 0.53 (0.22)
ER-MPH8 0.68 (0.20) 0.43 (0.25)
ER-MPH12 0.85 (0.13) 0.65 (0.22)
ATX 0.72 (0.14) 0.43 (0.19)
DEX 0.89 (0.14) 0.74 (0.24)
TABLE 100 Response rates defined as reduction of ≥ 25% on the ADHD-RS
Trial Treatment Responders (%) No. in group
Kelsey, 200463 ATX 79 (63) 126
Placebo 20 (33) 60
Michelson, 2002 74 ATX 50 (60) 84
Placebo 26 (31) 83
Kemner, 2004 99 ER-MPH12
ATX
[Confidential information removed]
Weiss, 2004 94 ATX
Placebo
Spencer, 2002 (reported results of 2 trials) 89 ATX 42 (65) 65
Placebo 15 (24) 62
Spencer, 2002 89 ATX 38 (59) 64
Placebo 25 (40) 62
of ≤1 on the SNAP-IV scale. In order to calculate
response rates, investigators averaged over the
teacher and parent ratings for each item on the
scale. The trial by Steele and colleagues 90 also
reported response defined as a score of ≤1 on the
SNAP-IV scale. Table 101 shows the response rate
information available on the SNAP-IV scale
(assuming that medical management in the MTA
trial is equal to IR-MPH). The nature of the
treatment received in the community comparison
arm of the MTA trial is still unclear, and as a result
these data are omitted from the analysis.
Hence in the final estimation of response rates, we
include all of the data from Tables 86, 98, 100 and
101. In other words, we synthesise response
defined on the CGI-I scale, CGI-S scale, ADHD-
RS and SNAP-IV scale, by estimating the
relationships between response defined on the
different scales. This final analysis also
incorporates data reported in Quinn 84 and the
results from Elia and colleagues. 51 [Confidential
information removed]. The study by Elia and
colleagues 51 used DSM-III diagnostic criteria and
defined response as a score of 1, 2 or 3 on CGI-I.
This increases the heterogeneity between studies
synthesised in this estimate of treatment effects.
119