Welsh Centre for Learning Disabilities, University of Wales College of Medicine, Cardiff
Hester Adrian Research Centre, University of Manchester
Welsh Centre for Learning Disabilities, University of Wales College of Medicine, Cardiff
Correspondence: Z. Ahmed, Welsh Centre for Learning Disabilities, Clinical Studies, Meridian Court, North Road, Cardiff CF4 3 BL
Declaration of interest Funding from the National Research and Development Programme for People with Physical and Complex Disabilities.
See editorial pp.
1011, this issue.
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ABSTRACT |
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Aims A randomised controlled trial was designed to investigate factors influencing antipsychotic drug reduction among people with learning disabilities prescribed such medication for behavioural problems.
Method Thirty-six participants randomly allocated to the experimental group under went four, monthly 25% drug reduction stages. There were no planned drug changes for the control group (n=20).
Results Twelve participants (33%) completed full withdrawal; a further seven (19%) achieved and maintained at least a 50% reduction. Drug reduction was associated with increased dyskinesia and higher activity engagement but not increased maladaptive behaviour. Some setting characteristics were associated with drug reinstatement.
Conclusions A substantial proportion of people with learning disability prescribed antipsychotic medications for behavioural purposes rather than for treating psychotic illness can have their drugs reduced or withdrawn.
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INTRODUCTION |
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This study was designed as a prospective randomised controlled trial to investigate the feasibility of antipsychotic drug reduction in such people with learning disability, and the factors influencing the outcome.
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METHOD |
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In total, participants received 12 different antipsychotic drugs, most frequently thioridazine (18 people, 12%), haloperidol (13, 23%) and chlorpromazine (8, 14%). Eleven participants (20%) were prescribed two antipsychotic drugs and five (9%) were prescribed three, not including p.r.n. medications. Five subjects were prescribed depot antipsychotic drugs. Forty-five participants (79%) had been prescribed the same drugs for five years or more. The mean daily chlorpromazine equivalent dose per participant was 372 mg (range 20-4067 mg, s.d.=613).
Instrumentation
Adaptive and maladaptive behaviour and uncontrolled movements were assessed
for each participant by using the Adaptive Behaviour Scale (ABS;
Nihira et al, 1993),
the Aberrant Behavior Checklist (ABC; Aman
& Singh, 1986) and the Dyskinesia Identification System:
Condensed User Scale (DISCUS; Sprague
et al, 1989). We measured weight by using standard
weighing scales. Medication history was abstracted from notes; subsequent
medication was monitored, with dosages converted to chlorpromazine
equivalents. In addition, the behaviour of each participant was observed
directly. Observers used palm-top Psion 3a portable computers (Psion plc,
London) programmed for multiple-category, real-time data capture (details
available from the first author upon request). Behavioural categories (and
constituent codes) included activity (engaged in an appropriate social
activity, engaged in an appropriate non-social activity, disengaged but
active, disengaged and not active), maladaptive behaviour (self-injury,
aggression to others, damage to the environment, other), stereotypy, and
staff involvement (assistance, praise, restraint, processing, i.e. doing
something to a person without their involvement, or other interaction).
Information on each participant's place of residence was collected by using a setting questionnaire designed for the study. This covered the following: the nature of the facility, building design, physical characteristics and building adaptations; the number, gender, age and general capabilities of residents; numbers, types and qualifications of staff; professional support; and working arrangements including budgetary control, arrangements for gaining assistance with behavioural difficulties, administration of p.r.n. medication, and guidelines and training for behavioural intervention, restraint and break-away strategies.
Design
Participants were allocated randomly to experimental (n=36) and
control groups (n=20). The two groups did not differ in age, but the
control group had fewer males (30% v. 58%; 2=4.1,
P<0.05) and a lower proportion living in hospital (25% v.
56%;
2-4.9, P<0.05). The proportions of the two
groups receiving various antipsychotic drugs at baseline differed by less than
10% in 10 out of the 12 types prescribed. The exceptions, which were still not
statistically significant, were thioridazine (experimental 25%, control 45%)
and haloperidol (experimental 28%, control 15%). The experimental group
received a significantly higher initial mean daily dose (460 mg, range 34-4067
mg (s.d.=717) v. 213 mg, range 20-1260 mg (s.d.=314), Mann-Whitney
U=208.5, P<0.01). The groups did not differ significantly
in weight, baseline ABS, ABC or DISCUS scores or in observed behaviour, with
the exception that the experimental group spent more time disengaged and
inactive (Mann-Whitney U=233, P<0.01). The only
significant difference in setting characteristics was that the average size of
the residential group for the experimental participants (ten) was
significantly greater than that for control participants (five) (Mann-Whitney
U=200, P<0.01).
Each participant was studied for six months. Baseline assessments (month 1) were followed by four, monthly drug reduction stages of 25% of the baseline chlorpromazine equivalent dose (months 2-5). The final month (month 6) was included to allow for any delayed changes in behaviour after drug cessation. There were no planned drug changes for the control group. Clinical consultants remained in charge of drug treatment for all participants throughout the study. Consultants were free to change medication at any time, including stopping drug reduction or reinstating baseline drug dosage.
The ABS, ABC, DISCUS and setting questionnaire were administered at baseline, and weight and medication regimen were recorded. In addition, behaviour was directly observed for a randomly selected 1.5-hour period during the second, third and fourth weeks of the month. In each subsequent month (months 2-6), behavioural observations were repeated at equivalent times. The ABC was also repeated at these times. The DISCUS and weight measurement were repeated in the fourth week of each month.
Analysis
Observational data were transferred to an IBM-compatible computer, and the
three periods of observation per participant for each month were arranged as a
single file set. Constituent codes for summary behavioural categories were
combined in order to eliminate concurrency of behaviours within the categories
but not between them. For example, total engagement in activity was a
combination of social and non-social activity, and total staff involvement
was a combination of all codes referring to any form of attention received by
participants from staff. The cumulative percentage durations of occurrence of
these categories and of the individual behavioural codes were calculated for
each participant for each month.
Given the sequential nature of the experimental protocol, it was important to analyse all dependent variables for sequence effects across the six time periods. A measure of linear trend in each variable was achieved by calculating regression coefficients for each participant across the data for months 1-5. (Month 6 was omitted from the analysis because of missing data caused by delays in identifying the last experimental and control participants taken into the study.) Between-group differences in these regression coefficients were compared by using t-tests. This approach was preferred to analysis of variance because it is sensitive to the temporal order of data.
Reliability
Inter-observer reliability for the direct observations was assessed by two
researchers observing simultaneously for nine hours (i.e. for about 11% of the
time). The level of agreement of the two observers was calculated for each
code by using a modified form of Cohen's
(Reeves, 1994). Summary values
of
across observation sessions were calculated as an average weighted
for the occurrence of the behavioural category in question. Values of
for social engagement, non-social engagement, maladaptive behaviour,
stereotypy, disengaged but active, disengaged inactive and staff involvement
were 0.63, 0.79, 0.75, 0.72, 0.61, 0.62 and 0.88 respectively. Suen & Ary
(1989) suggest that a value of
of 0.6 or higher is acceptable in observational research.
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RESULTS |
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The effects of drug reduction
The impact of drug reduction was explored through the comparison of the
success (n=19) and control (n=20) groups
(Table 1). Drug reduction was
associated with increased DISCUS scores and higher activity engagement, but
not with increased maladaptive behaviour. Staff contact with participants and
participant weight were unaffected. However, there were a number of
significant differences between the success and control groups at baseline;
the former had greater numbers of members who were the following: men
(2=4.3, d.f.=1, P<0.05); living in hospital
(
2=5.8, d.f.=1, P<0.05); living in a setting with
a specialist mental health orientation (
2=3.9, d.f.=1,
P<0.05); living in settings with lower staff to resident ratios
(Mann-Whitney U=94, P<0.02); receiving neuroleptic
medication for more than five years (
2=4.4, d.f.=1,
P<0.05); receiving higher chlorpromazine equivalent dosages of
neuroleptic medication (Mann-Whitney U=93, P<0.01).
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Predictors of drug reinstatement
Baseline comparisons between the success (n=19) and fail
(n=17) groups, and between the ten participants who failed to
progress beyond the first stage of drug reduction (nine immediately reinstated
to baseline dosages and one maintained at 75% baseline level) and the 26
participants who proceeded to the 50% reduction stage, revealed a number of
significant differences between the settings in which participants lived
(Table 2). Variables concerning
restrictiveness of the setting and the policy and training of staff in
relation to use of physical restraint and break-away techniques were
consistently implicated. In neither analysis were there significant
differences on any measure of participant ability, maladaptive behaviour or
medication status other than the failure to progress group in the second
analysis being less able in physical development (Mann-Whitney U=63,
P<0.05) and vocational activity (U=75.5,
P<0.05) on the ABS and being less likely to receive depot
neuroleptics (2=4.6, d.f.=1, P<0.05).
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Finally, analyses examined changes between baseline and the first drug reduction stage for the failure to progress and further progress (i.e. from 100% to 75% of baseline dosage) groups. The only significant change on any dependent variable for the failure to progress group was a reduction in score on the inappropriate speech sub-scale of the ABC (t=2.5, d.f.=9, P<0.05). The further progress group showed a significant reduction in score on the hyperactivity sub-scale of the ABC (t=2.3, d.f.=25, P<0.05). Combined analyses using a multivariate analysis of variance (MANOVA) model did not identify significant interaction effects.
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DISCUSSION |
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Drug reduction was associated with increased DISCUS scores, a finding consistent with the literature on tardive dyskinesia emerging upon withdrawal of neuroleptic medication (Baumeister et al, 1998). The increase in movement disorder became significant at month 4, at which time 18 out of 19 people in the group were down to 25% of the baseline drug dosage (i.e. dosage was reduced by 75%). Movement disorder reached its maximum level at month 5, when 13 out of 19 people in the group had ceased to take antipsychotic drugs. There was a decline in DISCUS scores at month 6 relative to month 5, but scores remained higher than those at baseline.
Drug reduction was also associated with significantly higher engagement in activity. This is an important outcome, because engagement in activity has been a widely used indicator of quality of life, particularly in studies of residential settings for people with severe learning disabilities (Emerson & Hatton, 1994). As well as indicating greater purpose and productivity, increased engagement also signifies greater alertness and environmental responsiveness. Increased engagement following drug reduction would be consistent with reduced sedative effects and increased coordination and general physical well-being. An impression of greater alertness was confirmed by anecdotal staff accounts. However, increased engagement in activity among the success group was only marginal, while a slight reduction in engagement over time in the control group also contributed to the difference between the groups. The consequences of drug reduction for responsiveness and quality of activity require further research.
There were indications of an anticipated weight loss among the success group at months 5 and 6, with average weight losses of 1.6 kg and 2.3 kg respectively. Weight loss was seen as a benefit in some participants because they were overweight, possibly as a result of prolonged antipsychotic medication. Weight loss was problematic in only one participant, a member of the fail group who had a 4 kg loss of weight after 75% drug reduction; she also showed a decrease in appetite and behavioural deterioration. Appetite and weight returned after drug reinstatement; it is possible that this individual experienced non-dyskinetic withdrawal syndrome (Gualtieri et al, 1986).
Predictors of drug reinstatement
Analysis of differences between the success and fail groups and between
the failure to progress and further progress groups consistently failed to
implicate level of problem behaviour or prior medication status as predictive
factors. Reinstatement was not associated with deterioration of behaviour
derived from either staff report measures or independent observations. That is
not to say that on a case-by-case basis specific incidents may not have
occasioned drug reinstatement. Clearly, participants continued to exhibit
maladaptive behaviours. Instances of such behaviour among those having their
medications reduced may have been attributed to drug reduction and caused a
decision to reinstate original dose levels. However, what is shown is that
drug reinstatement was not associated with either a higher level of
maladaptive behaviour or a worsening of maladaptive behaviour overall.
Clinical attitudes and influences
The issue of attribution is one example of the possible impact that
clinical approach, staffing and environmental characteristics may have on the
likelihood of drug treatment for behavioural problems being pursued and
maintained. Where differences on the variables measured in this study were
apparent between participants for whom drug reduction was successful or
unsuccessful, they were mainly in staff and environmental characteristics. In
particular, drug reinstatement was associated with greater restriction and
adaptation of the setting, less conducive staffing arrangements in certain
respects and less well developed policies and poorer staff training concerning
responding to difficult behaviour. The confidence of clinicians and carers to
cope with possibly transient fluctuations in behaviour seems to be an
important factor in the determination necessary to see whether any initial
adverse reactions to withdrawal can be tolerated and drug reduction sustained.
Staff attitudes and apprehension may play important roles in determining drug
reduction outcome. Training staff in how to diffuse and cope with problem
behaviour when it occurs can increase staff confidence
(McDonnell, 1997). The
following two examples of the reasons for drug reinstatement illustrate the
importance of the position that staff take.
A woman who lived in a staffed community residence showed an increase in stereotypy, aggression and irritability upon withdrawal of antipsychotic medication. Initially, care staff coped with this behaviour, hoping that it might prove temporary. However, although her behaviour had not deteriorated further, she kicked the pet dog during a period of excitement and it sustained fatal internal injuries. This had a marked effect on the emotional state of the carers, and her antipsychotic medication was reinstated to baseline dose. In the second example, another four participants allocated to the experimental group all lived in one hospital unit. Staff were anxious about drug reduction. After the first 25% drug reduction stage, one of the four was felt to have deteriorated behaviourally. Consequently, all four participants were put back on their baseline dosages even though no deterioration in behaviour was considered to have occurred in the other three participants.
Lessons for practice
Despite case reports of pharmacological management of behavioural symptoms
among people with learning disabilities, an international consensus conference
recently re-emphasised the scarcity of systematic research on pharmacotherapy,
and pointed to the persistent problem of over-prescription of neuroleptic
medications for behavioural management
(Reiss & Aman, 1998). The
present study has confirmed that a substantial proportion of people with
learning disability prescribed antipsychotic medications for behavioural
purposes rather than psychotic illness can have their drugs reduced or
withdrawn. It is likely that this proportion can be increased if favourable
clinical approaches and environmental conditions can be made more common. This
study suggests that these improvements should include more rigorous
behavioural assessment and causal attribution of behaviour change, more
attention being given to the proportion of experienced and full-time staff,
and an investment in initial and refresher staff training courses on
responding to difficult behaviour, rather than an undue reliance on
environmental restriction or adaptation.
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Clinical Implications and Limitations |
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LIMITATIONS
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ACKNOWLEDGMENTS |
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Received for publication January 4, 1999. Revision received September 16, 1999. Accepted for publication September 21, 1999.