Abstract
Abstract: :
Purpose: The effectiveness of a self–administered eye drop medication even in clinical trials can only be assessed if the compliance is known. To know the compliance of the patients may prevent from visual loss. We studied the specificity and sensitivity of a new programmable, microprocessor–controlled monitoring device that can easily be mounted on most commercially available eye–drops. Methods: The monitoring system was equipped with an 8bit microprocessor, program–ROM, program–RAM, EEPROM for data storing, analogue–to–digital converters for sensor readings, in–out ports for the PC interface and a battery. Sensors measuring applied force/pressure to the bottle, temperature and vertical position of the bottle were connected to the system. Ten devices were mounted on commercial 5ml eye–drop bottles: total weight 21.5g; height 74mm; diameter 25mm. Test subjects had to protocol each dummy–application following a schedule. Bottles had to be carried around with other personal belongings or to be kept in the fridge. A total of 15 applications each were intended. After 3 days all bottles and protocols were collected for data analysis. Results: Manual protocols confirmed 15 applications for each of the 10 bottles. The monitoring devices detected a total of 149 events; one was missed; comprising a sensitivity of > 99%. Two devices registered a total of 3 applications which did not occur in the manual protocols, indicating a specificity of about 98%. The application of 3 refrigerated bottles was correctly identified by the temperature sensors. The observed battery lifetime was > 60 days. Conclusions: The new monitoring device demonstrated a high reliability of the collected compliance data. The important jet unknown influence of compliance in patient care and clinical trials shall be illuminated by the new device. This may lead to a better adapted patient care. Studies will profit from a higher creditability and results less influenced by non–compliance.
Keywords: clinical (human) or epidemiologic studies: systems/equipment/techniques • clinical research methodology