Chip in the pill

Next-generation pills are being developed by scientists, the Los Angeles Times and the Financial Times report.

These high-tech pills are equipped with microchips, that report back exactly when, what kind of and how much medicine the patient has taken.

The main goals of these new devices are to help the patients adhere to their medication regimen and to improve adherence to medication in clinical trials.

Examples for the high-tech pills

Magne Trace

Investigators from Georgia Tech developed an electronic necklace that can detect magnetized pills as they pass through the esophagus. The necklace (or a patch attached to the chest) contains a magnetic sensor that could be used to detect when specially-designed medication containing a tiny magnet – three millimeters in diameter and about one millimeter thick – passes through the patient’s esophagus. The date and time the user swallowed the pill can be recorded on a handheld wireless device, such as a smart phone, carried on the user’s body. The information can then be sent to the patient’s doctor over the internet. The device can notify both the patient and the patient’s doctor if the prescribed dosage is not taken at the proper time.

Proteus

Proteus Biomedical and Novartis developed a specialized microchip which the company plans to add to pills. When a patient ingests a ”Proteus-pill”, their stomach acids activate the microchip, which then sends data such as heart rate, temperature, and body movements to a dermal patch via Bluetooth connectivity. This patch can then export the data to an EMR (electronic medical record), so that it can be accessed by the patient's doctors. Novartis will bring the "Proteus-pills" to market within two years.

  

ID-Cap 

The ID-Cap is a sticker that is developed by University of Florida electronic engineer Rizwan Bashirullah. The cap contains a microchip, antenna and acid sensor and it sends electronic signals through body tissue to a receiver, worn on the wrist. Bashirullah estimates that applying the microchips to medication would cost between 25¢ to $1.00 more per pill, and that a real-world product should be available within two years.

House M.D. - Patient education and better physician–patient relationship increase the effectiveness of treatments

There are many causes of non-adherence in patients with asthma, such as lack of prescription refills, discontinuation of the therapy or incorrect use of the medication (incorrect inhalation technique)…………

Secondary database analysis: models for measuring medication adherence and persistence

Secondary database analysis is a common used process to evaluate patients’ drug taking behaviour. There are more standardized models for measuring adherence and persistence.

Medication adherence:

Medication Possession Ratio (MPR):

• MPR:    number of days of medication supplied within the refill interval / number of days in refill interval
• At least two fill dates are needed to calculate this ratio.
• Numerator: total X days of supply
• Denominator:
• last refill as the end point 

                        total X days of supply              

last X date – fisrt X date + last X days of supply

• fixed interval (e.g. seasonal diseases) 

total X days of supply

            fixed interval (X days)

• Dual or triple therapy (e.g. hypertension): the numerator must be / with 2 or 3
• MPR is a dichotomous various (adherent / non-adherent).
• Cut-off value is disease specific.
• Conventional: patients with adherence over 80% (MPR) can be called adherent.
• Overuse: MPR is over 1.0 (100%), these patients are also non-adherent !

Proportion of days covered (PDC):

• PDC: the number of days with all drug(s) on-hand / the number of days in the observation interval.
• PDC values range from 0 to 1.

MPR vs. PDC : Is the patient adherent?

Drug

Months 1-12

Supply (days)

A

x

x

x

x

x

x

x

x

x

9x30=270

B

x

x

x

x

x

x

x

x

8x30=240

C

x

x

x

x

x

x

x

7x30=210

↑

↑

↑

3x30=90

MPR: ((270+240+210)/3) / 360 = 0.66

PDC: 90 / 360 = 0.25

Medication peristence:

• The duration of time from the initiation (or at chronic disease from an optional date) to the discontinuation of drug therapy. (Permissible gap: is reported as the maximum allowable period of the refill interval without discontinuation of the therapy.)
• Percentage of individuals remaining on therapy (persistent) until a specified time interval.

Patients persisted x days vs. y patients were persistent for z days

Patient

Months 1-12 (1 month = 30 days)

Days persistent (gap=30 days) *

Persist 180 days (gap=30 days) **

A

x

x

x

x

x

x

x

120

no

B

x

x

x

x

x

x

x

x

180

yes

C

x

x

x

x

x

x

60

no

*: patients persisted on avarge 120 days ((120+180+60)/3) **: 33% (1/3) of the patients were persistent for 180 days

References

Martin BC, Wiley-Exley EK, Richards S, Domino ME, Carey TS, Sleath BL.Contrasting measures of adherence with simple drug use, medication switching, and therapeutic duplication. Ann Pharmacother. 2009 Jan;43(1):36-44.

Karve S, Cleves MA, Helm M, Hudson TJ, West DS, Martin BC: Prospective validation of eight different adherence measures for use with administrative claims data among patients with schizophrenia. Value Health. 2009 Sep;12(6):989-95.

Peterson AM, Nau DP, Cramer JA, Benner J, Gwadry-Sridhar F, Nichol M: A checklist for medication compliance and persistence studies using retrospective databases. Value Health. 2007 Jan-Feb;10(1):3-12.