A) Optimal Medication Monitor(s) and Method of Retrieving Adherence Record.
B) Other Dose Removal Monitors.
Retrieval of clinical data stored in the monitor
When a patient moves and is treated by a different clinic than the one which initiated his therapy, when a patient begins working with a different caregiver, or when clinical records are lost, it would be useful to have basic clinical records stored in the monitor. This information might include the patient’s HIV status and sputum status for each clinic visit.
For the caregiver to be able to retrieve this clinical data through the monitor’s display, the monitor would generally need to have either a matrix display or a character display (e.g. 2-digit display).
Rather than being required to step through the complete adherence record to get to the display of clinical data, the caregiver should be able to access this data by entering some special code. In the case of a monitor having a separate caregiver’s button, as described above, this code could be as simple as simultaneously pressing the caregiver’s button and the patient’s button.
The following is an example of how the clinical data might be presented by 5 x 7 matrix display:
Upon entering an appropriate code the display would show the HIV status of the patient. H with a P, if HIV positive, H with a negative sign, if HIV negative, and H with nothing, if the HIV test was not done.
With the next push of the button the results of the first sputa test would appear: S with a P if the patient was sputum positive. S with a negative sign, if the patient was sputa negative, and S with nothing if no sputa test had been done.
With subsequent depressions of the button the sputa status in subsequent months would be given for each of the months since the patient was started on medication. Since sputa tests are usually not done every month, most of these displays would show S with nothing. A patient, who had a positive sputum the first month, no sputa for 3 months and negative sputum on the last month, would have the following sequence of displays.
With subsequent depressions of the button additional items of clinical information could be given such as:
P+ for prior treatment(red) P- for no prior treatment (green).
d+ for known drug resistance (red), d - for known drug susceptible (green), and d 0 for no drug susceptibility test done (yellow).
Further notes on information retrieval
Additional display functions
Obviously, additional information could be shown with the monitor’s display.
One example of additional information which could be useful would be an assessment of how consistent a patient was in taking medication near the same time each day. There is some evidence that patients who take medication near the same time each day tend to be more consistent in taking their medication every day rather than missing occasional days. This potentially useful assessment could be represented by different color lights or as a numeric value, or both.
For any additional information shown, decisions would need to be made as to how the information would be presented with the display and how it would be accessed.
Red/green LED Dot matrix display
The Red Green Dot Matrix display may be easier to understand than the sequential single red/green/yellow display, and could more easily transmit clinical information about the patient, but it would be modestly more expensive and more difficult to transmit over a telephone.
A dot matrix display consists of a rectangular array of display elements, commonly LEDs. Dot matrix displays are made in several patterns form 4x4 up to 16x16 or larger. The most common configuration is a 5x7 array which is designed for displaying any single letter or digit as well as numerous other dot patterns. Among these other patterns are simple displays of 2 digits equivalent to those possible with the 2-digit character display. While many matrix displays use a single color, 5x7 matrix displays are also available with a red/green LED for each dot.
A red/green matrix display combines all of the functionality of the red/green LED with that of the 2-digit display. Furthermore, the 5x7 matrix display seems particularly well suited for displaying a patient’s detailed adherence record since each of its 35 dots can represent one day; and the color of the dot can represent medication removed (green), medication not removed (red), or several doses removed (yellow flashes), as described in the section Using the monitor’s display to retrieve the adherence record below.
Using a Dot Matrix Display to determine the battery status
Normally, the battery status and adherence record would not be available to the patient and would only be accessed by the caregiver. The caregiver might access this information by simply pressing a separate “caregiver’s button” which is not accessible to the patient. This could be a button which can only be accessed when the monitor is opened, as it would be when the dispenser is refilled with medication.
When the caregiver pushes the button the first time a line of lights in the matrix display will shown green if the battery is fully charged, yellow if the battery is partially charged, and red if the battery needs replaced.
The single line of lights was chosen to indicate the battery status since this would not be confused with a display of any other information.
Using a Dot Matrix display to retrieve the adherence record
When the caregiver pushes the button again the panel for the most recent refill interval would appear. The left hand upper corner would show flashing green (indicated here by a starburst ) for the day that the device was last filled. Patients who were good compliers and returned on time in four weeks would have 28 green dots, each indicating a day on which medication had been removed. If the patient had a poor adherence record red dots would also be present, with each red dot indicating a day on which medication had not been removed.
If the patient’s monitor had not been refilled for more than 35 days, a second and maybe a third panel would automatically appear after a few seconds in order to show all missed days with red dots. When the last red dot was reached the first panel for the first refill interval would once again automatically appear.
When the caregiver pushes the button again the first panel for the preceding refill interval would appear. Again, if the patient’s monitor had not been refilled for more than 35 days, a second and maybe a third panel would automatically appear after a few seconds in order to show all missed days with red dots. When the last red dot was reached the first panel for the refill interval being reviewed would automatically appear..
Each successive button push would bring up the panel for the previous refill interval.
When there were no more refill intervals to be displayed and the caregiver pushed the button again the matrix would show a unique symbol which would tell the caregiver that there we no more refill intervals to review. (This symbol could flash to draw attention.)
At this point the caregiver has to decide how to manage the patients based on all adherence records. Should he give a 28-day supply, a two-week supply, should he continue therapy for more than 6 months, and should he plan for additional home visits for educating the patient and family.
Therefore, I think it would be reasonable that the next push of the button brings up the most recent refill interval and subsequent pushes of the button goes through the entire compliance record again.
This matrix display could also distinguish pocket doses from catch up doses. Pocket doses are multiple doses removed on one day before they are to be ingested, usually because the patient wants to have medicine available to take on a trip, Catch up doses are multiple medications removed on one day to make up for doses not taken in an effort to deceive the care giver.
If five pocket doses were removed on one day with four of these to be taken while on a trip, the dot for the day when five doses were removed would first flash green followed by four yellow flashes; and subsequently 4 red dots would appear for days while the patient was on the trip.
By contrast the patient might remove multiple doses on one day in a futile attempt to keep the care giver from knowing he missed taking medication. For instance, if the patient missed taking doses for four days, four red dots would appear followed subsequently by a dot which flashed green once and yellow four times.
With the matrix display, it would normally be easy to distinguish advanced removal from catch up removal, as illustrated by the two calendar displays above. However, more complicated patterns would sometimes be seen; and their interpretation would depend upon the caregiver’s judgement .
While the patterns for pocket doses and catch up doses look similar, the caregiver needs to remember that they represent significantly different degrees of adherence. If the pattern shows pocket doses were removed the patient may or may not have ingested the medication on the subsequent days when the display shows red dots. If the pattern shows catch up doses were removed the patient clearly did not take medication on the preceding days where the display shows red dots.
Character displays use line segments to form characters (numbers or letters). Both LED and LCD (liquid crystal display) character displays are available. LED character displays are available for displaying a single character or a small number of characters with each display module, while LCD displays are generally designed to show a larger number of characters. Where only a few characters are needed, LED displays are more economical.
Some character displays incorporate enough segments to fully form an alphanumeric character set including all digits and all letters of the alphabet. Others, such as those normally used in calculators, are designed to display only digits, but can also display a limited set of letters. These normally have seven segments for each digit.
A 2-digit seven segment display like that shown at the right would be adequate for use in a medication monitor. Such a display has the advantage, relative to the single red/green LED, of being able to show numeric values. For example, the 2-digit display could show the number of pills a patient should take, the number of doses remaining in the dispenser, or the percentage of days on which the patient removed medication. The 2-digit display can also show a limited number of letters, A, b, c, E, F, H, J, L, n, P, r, and U, which can be useful if clinical data is to be retrieved from the monitor. (See: Retrieval of clinical data stored in the monitor below.)
The 2-digit display, however, does not share the red/green LED’s ability to use different colors.
One inexpensive 2-digit display (as of June 24, 2010) is:
LITE-ON Manufacturer’s no. LTD-482P-YQ ($0.89 each in thousands from Jameco Electronics)
Use of 2-digit display for reviewing battery status and adherence record
A two-digit display, which costs approximately $0.89, could also be used to report the battery status and adherence.
With the first push of the button the display would show the charge of the battery with the letter b and any number from 1 to 9 for the charge remaining in the battery.
With a second push of the button the display would show the percentage of medication, which had been taken since the last refill anywhere from 0 to 99% with 99% displayed when the adherence was perfect.
Subsequent pushes of the button would provide the percentage of medication that had been taken in previous refill intervals.
When all refill intervals had been displayed the display would create a distinctive symbol like repetitively flashing 1,2,3,4,5 multiple times to indicate there were no more refill intervals to review.
This two-digit display while somewhat less expensive than a Dot Matrix Display has several limitations.
First, if the patient was one or more months late in returning for refills of medication, the caregiver would get a record of poor adherence, but might not realize the patient was several months late in returning for a refill, a piece of information useful in planning interventions that would have been picked up if the red/green matrix LED had been used
Second, the caregiver could not get a detailed adherence record without entering codes and stepping through the adherence record for each day one by one, a process, which would be tedious and time consuming.
Third, the caregiver could not distinguish pocket doses from catch up doses without going through the tedious process of stepping through the adherence record for each day.
Single red/ green LED for displaying a summary adherence record and battery status
The single red/ green LED previously described in section on communication functions could be used to obtain a summary of the adherence record and battery status.
With the push of the button the LED would first flash green multiple times if the battery is fully charged, yellow multiple times if the battery is partially charged, and red multiple times if the battery needs replacement.
With a second push of the button the LED could provide a summary of the percentage of days on which medication had been taken since the last refill as follows.
Subsequent pushes of the button would provide the summaries of the adherence record in previous refill intervals.
When all refill intervals had been displayed the LED would sequentially flash green yellow red multiple times to indicate there were no more refill intervals to review.
This less expensive simple display has several limitations.
First, if the battery needed replacement and multiple red flashes occurred with the first push of the button, the caregiver might incorrectly interpret this as poor adherence.
Second, if the patient was one or more months late in returning for refills of medication, the caregiver would get a record of poor adherence, but might not realize the patient was several months late in returning for a refill, a piece of information useful in planning interventions that would have been picked up if the Red/Green Dot Matrix display had been used
Third, the caregiver could only get a detailed adherence record if the microprocessor was programmed as described in the section Retrieval of Adherence Record in Patient’s home using Red/Green/Yellow LED.
Fourth, the caregiver could only distinguish pocket doses if the microprocessor was programmed as described in the section Retrieval of Adherence Record in Patient’s home using Red/Green/Yellow LED.
Fifth, the caregiver could not get any clinical data stored in the monitor.