An online survey of 2,507 U.S. adults conducted between March 16 and 18, 2005 for The Wall Street Journal Online’s Health Industry Edition indicated that "one in three (33%) U.S. adults who have been prescribed drugs to take on a regular basis report that they are often or very often noncompliant with their treatment regimens for any number of reasons. Furthermore, nearly half (45%) say they have failed to take their medications because of concerns they had about the drugs themselves, and 43 percent report having not complied with their regimens because they felt the drug was unnecessary."
Clearly, patient non-compliance is a crucial health literacy issue that affects national health care costs. Non-compliance is suspected as the major reason for rejection of organ transplants, for example. The set of simulation learning objects below are designed to help visualize the effects of non-compliance.
Prescribed drug regimen: 2 (two) 150 mg pills every 8 hours for 7 days. The plasma concentration is the concentration in the central compartment C1, plotted in red. The user-adjustable toxic and minimum therapeutic concentrations are set in this example relative to plasma concentrations because they are more readily measured. Obviously, the thresholds in the simulation can be set, if desired, relative to the effect site concentration in compartment C2, plotted in blue. Toxic concentration: 1.00 mg/L; Minimum therapeutic concentration: 0.21 mg/L. View this scenario.
Effect of missing a dose: In the following simulation, the plasma concentration drops below the minimum therapeutic level for a significant time. View this scenario.
Effect of "making up" for missed dose at next dose interval: The simulation shows the consequences of "making up" for the missed dose by doubling the dose at the next dose interval. The plasma concentration exceeds the toxic level after the dose is doubled as well as briefly after the following dose interval. View this scenario.
Effect of halving the dose to "save money": The plasma concentration is below the minimum therapeutic level for approximately half of the time. View this scenario.
Effect of halving the dose after 2 days once the therapeutic level has been reached and symptoms abate: The plasma concentration is below the minimum therapeutic level for approximately half of the time after the dose is halved. View this scenario.
Effect of taking twice the prescribed dose: Here the pills instead of each representing 150 mg are set to represent 300 mg for a total dose of 600 mg for 2 pills. The plasma concentration is above the toxic level for about half of the time. View this scenario.
References
Harris Interactive® online survey; The Wall Street Journal Online’s Health Industry Edition