Skip navigation
Link to Back issues listing | Back Issue Listing with content Index | Subject Index

Dose regimens and compliance

Systematic review
Results
Comment

Bandolier 117 looked at a rather old (1984) review of dosing regimens and compliance, that concluded that once or twice a day regimens had better compliance (about 70%) than those in which patients had to take medicines three or four times a day. There were some problems with it, one of which was that it used pill count, interviews, and presence of drug in body fluids to assess compliance. A new systematic review of electronic monitors [1] comes to the same conclusion.

Electronic monitors use microprocessors to record the precise time that a dose is removed from the monitoring unit, and capture medication events. They record both the number of events, especially whether doses are missed, and whether doses are taken at the correct time.

Systematic review

The review used five electronic databases, including the Cochrane Library, to find reports of electronic monitoring use. Any device could be used, and medication compliance had to be reported. Studies for the years 1986 to 2000 were sought. Results were evaluated in terms both of the number of doses taken, and also the timing of doses to within 25% of the dosing interval. For 12 hour dosing, therefore, doses taken outside of plus or minus three hours were deemed inappropriate.

Results

The review found 76 studies with identifying dose taking or dose timing. Most (60) were bottle caps, 10 were metered dose inhalers, and two each pill boxes, blister cards, or eye drop dispensers. The majority of conditions were in cardiovascular and respiratory disease, though there was little difference in overall compliance between conditions, perhaps with the exception of respiratory disease where it was lower at about 50%.

Overall compliance for taking doses in 85 different regimens was 71%, with a range of 34% to 97% in individual studies. Once and twice a day dosing was higher than that for three and four times a day regimens (Figure 1). For dose timing in 14 reports, the proportion of medicines taken within the prescribed time was 58% for twice daily doing, and below 50% for three and four times a day dosing (Figure 2).



Figure 1: Compliance - dose taking







Figure 2: Compliance - dose timing





Comment

For dose taking compliance, the results here using electronic monitoring were substantially the same as those found in the older study using pill counts or patient interviews (Table 1). The results for timing were similar. Perhaps the lesson is to keep it simple, difficult though that is, particularly in older people with several conditions.



Table 1: Compliance in dose taking



1984 review
New review
Times a day
Range
Mean (SEM)
Range
Mean (SEM)
Once
42-93
73
35-97
79
Twice
50-94
70
38-90
69
Three times
18-89
52
40-91
65
Four times
11-66
42
33-81
51


Reference:

  1. AJ Claxton et al. A systematic review of the association between dose regimens and medication compliance. Clinical Therapeutics 2001 34: 1296-1310.

previous or next story