Transcript No Slide Title

Controlling “Polypharmacy” in the elderly
The “Medication Appropriateness Index”
G. Vital-Durand 1, F. Herrmann 2, J-P. Michel 2, V. Rollason 3, N. Vogt 3, P. Dayer 3
Centre Suisse de Pharmacovigilance 1, Berne, Hôpital de Gériatrie 2 and Unité de Gérontopharmacologie Clinique 3, Geneva, Switzerland
Table 1
1. Introduction
« Polypharmacy » may be defined as drug use that is both inappropriate and
excessive1. Previous researchers have analysed this practice and pointed to
its many pitfalls 2-4. Some of the likely causes for such common abuse have
been identified and various procedures have been applied to tackle it 5-7.
We undertook a controlled study following a randomised, parallel, single-blind
design in two groups of elderly hospitalised patients in order to test
a quality control (QC)-procedure called Procédure de validation de
la prescription (PVP) or Medication Appropriateness Index (MAI)8. This
procedure has been developed as a practical tool intended to help physicians
validate their patients’ prescriptions.
MAI* Application (for each of the drugs)
Indication
[3]
2.
Effectiveness
[3]
3.
Dosage
[2]
4.
Instructions for use
5.
6.
2. Study procedure
Patients’ drug use was assessed both prior to and following application of
the QC-procedure. « Polypharmacy » was defined as the administration of
> 5 drugs over a 3 day-period upon hospital admission. In the active group,
house-officers were advised of any prescription inappropriateness (on
the basis of the MAI score), whereas in the control group, MAI results were
not disclosed. Drug prescription data was collected and analysed so as to
minimise the observation bias. Variations of prescription patterns were thus
identified and measured so as to assess the impact of the QC procedure.
Finally interviews were conducted with the house-officers to assess their
receptivity to the intervention. We intend to conduct multivariate comparison
tests both sequentially within groups and also between groups at similar
periods at a later stage.
see Table 1
200 newly admitted patients were included in the study, 100 of which in
the active group. We present here the results obtained on the basis of an
interim analysis of the first 162 patients screened for the study.
« Polypharmacy » was identified in 100 patients (62 %) with 9.6 drugs per day
on average. These first 100 patients were then randomised into either an
active or a control group. Both groups were comparable insofar as age,
gender, documented medical history or prescription pattern was concerned.
The average number of drugs administered was 9.2 in the active vs. 10.0 in
the control group. All patients were administered the QC procedure and the
corresponding MAI scores were computed.
Of the 10 targets tested in the MAI score, those dealing with costeffectiveness (once per patient on average [= score 1]), efficacy [score .6] and
ADR’s* [score .3] were the most commonly missed.
As far as the drugs assessed as inappropriate, they mostly fell into the cardiovascular, CNS and G-I categories.
see Figure and Tables 2 & 3
T 2w - Active
T 2w - Control
Indication
Indic.
N/pat.
Score
0.48
0.98
[2]
Drug interactions
[2]
CNS
0.42
0.60
Clinical interactions
[2]
G-I.
0.28
0.48
7.
Other ADR’s**
[2]
Antim.
0.03
0.10
8.
Duplication
[1]
NSAID
0.07
0.07
Drug inter.
9.
Duration of treatment
[1]
Others
0.08
0.15
Clin. Inter.
Institutional Drug directory
[1]
Total :
1.36
2.38
10.
Effectiveness
Dosage
Instructions
Other ADRs
Total : [19]
*
**
T0
Typical inappropriate
prescriptions (at T 0 )
Cardvasc.
Medication Appropriateness Index
Duplication
Adverse Drug Reactions
Note : The higher the score, the least
appropriate the drug
Duration
Directory
Table 3 – Results (among 100 randomised patients)
0
T0
3. Results
3.1. Extent and nature of “Polypharmacy”
Figure - Score items
Table 2
Score
1.
* Adverse drug reactions
Contact : [email protected]
0.2
0.4
0.6
0.8
1
1.2
1.4
T 2w (2 weeks)
Total [n = 100] Active [27] Control [32]
N of prescriptions (average)
9.6
8.9
9.5
N of inappropriate prescriptions (av.)
1.4
1.5
1.4
MAI score (average)
2.4
2.3
1.7
4. Conclusions
• « Polypharmacy » is a common occurrence in the context of a
reference teaching hospital for elderly patients.
• The MAI procedure appears to offer a valuable tool to assess
the validity of drug prescriptions in elderly hospitalised patients.
• Furthermore, application of the MAI procedure is feasible by houseofficers themselves rather than clinical pharmacology or pharmacy
consultants.
3.2. Impact of the MAI Procedure
Two weeks later, patient records were revisited and the same QC
procedure was again administered. Those not available for review (dropouts) fell into such categories as discharge and death (42 %). From those
58 patients who were assessed a second time (Protocol-evaluable
category), the following data (average figures) was extracted.
Even though the average number of drugs taken in the active group was
lower than that in the control group (8.9 vs. 9.5), both the number of
inappropriate prescriptions and the MAI score were not significantly
different between the two parallel groups.
see Tables 2 & 3
• Further investigations are warranted to validate the application of the
procedure by house officers themselves rather than outside observers.
References
1 - Hanlon JT et al. Amer J Med 1996 ; 100 : 428-37. 2 - Himmel W et al. Eur J Clin
Pharmacol 1996 ; 50 : 253-7. 3 - Emeriau JP et al. Bull Acad Nat Méd 1998 ; 182 (7) :
1419-29. 4 - Salles-Montaudon N et al. Rev Méd Int 2000 ; 21 (8) : 664-71.
5 - Beers MH. Arch Int Med 1997 ; 1531-6. 6 - Le Grand A et al. Health Policy Plan
1999 ; 14 (2) : 89-102. 8 - Gurwitz JH et al. J Am Geriatr Soc 1990 ; 542 : 542-52.
8 - Fitzgerald LS et al. Ann Pharmacother 1997 ; 31 (5) : 543-8.