Compliance with anti-tuberculous therapy: a field trial of a pill-box with a concealed electronic recording device.

We have conducted a field trial of a pill-box containing a concealed electronic device for monitoring compliance in 23 consecutive adult out patients taking a rifampicin/isoniazid combination once daily. In 22 cases, the times when the box was opened were successfully recorded for the entire period (mean (SD) 26 (5) days) between successive clinic visits. In the other patient the record terminated after one week, a broken box being returned. Both totality of compliance (as assessed by box openings) and consistency of compliance (the proportion of the total number of intervals between openings which were of 22 to 26 h in length) were significantly greater in those studied in the intensive than in the maintenance phase of therapy. Patients may have taken the reduction in medication at the end of the intensive phase as signalling cure. A computer program has been developed to display the recorded data. This allowed the physician responsible to assimilate at a glance the patient's tablet-taking habits. In routine practice knowledge of the presence of the device may improve compliance and a discussion of the graphical display may prove of value in counselling.