High rate of errors in pillbox filling by cognitively healthy elderly people

An appropriate medication management depends on executive system integrity, which can be affected by aging. Previous studies showed that seniors commit frequent errors when having to fill in a pillbox. Nevertheless, to the best of our knowledge, no study has really considered the absence of cognitive disorders in the studied sample. The present study aimed to investigate pillbox filling in cognitively healthy elderly (specially focusing on executive system preservation) for whom no cognitive deterioration neither any depressive episode had occurred during a one year period. The filling task has been completed using a weekly pillbox and eight fictitious drugs. The selection of the 27 seniors aged from 71 to 90 years has been based on their results to neuropsychological tests (Trail making test, Stroop Victoria, Tower of London, Montreal cognitive assessment) and a depression assessment scale (Short geriatric depression scale). Results showed that 67% of the participants committed at least one error when filling the pillbox and 56% at least 3. The maximal number of errors was 38. Further, the errors analysis showed that 85% of the errors had been repeated (e.g. reproduced on several days). Finally, the more complex the drug prescriptions are, the higher the error rate is. No other variable (age, gender, level education, habit of filling a pillbox) had any effect on the number of errors. So, the pillbox filing task can be considered as a complex task associated with a high risk of errors. Moreover, the absence of cognitive disorders is not a success factor to the task. A prospect for the future should be to try to limit the error rate by developing, for instance, an external support helping to the filling of the pillbox and a learning process for the use of this support.