Previous research has shown a correlationbetween negative clinical outcomes in the elderly and complex medicationregimens. Medication regimen complexity has been shown to predict the abilityof these patients to manage their medicines. There is a known association between increasesin medication regimen complexity and self- administration errors.4A study by Shirley S.
Travis, et al (2007), identified the potential factors associatedwith medication administration difficulties among caregivers who providedlong-term medication assistance to older adults. This study found that family caregivermedication administration problems increased with medication regimen complexity. Thestudy suggested that complex medication regimens of individual patients couldbe used as a marker to help identify caregivers at risk of experiencingdifficulties with medication administration, as well as being a potential riskfactor for caregiver stress.82 Caregiver stress may negatively impact thecare delivered to the patient.Studies by Schoonover et al (2014) showed thatan increase in MRCI score increased the probability of adverse drug events(ADE) by more than four-fold. The study also reported that there is a 5.45times higher odds of hospital readmission within 30 days for patients withhigher MRCI scores compared with those with lower scores.83 A population study in Sweden produced similarresults.
This study measured the time to the first unplanned hospital admissionover a 3-year period, and showed that complex medication regimens were associatedwith unplanned hospital admissions.84 Another study using people over the age 60 incommunities and institutions investigated the relationship between medication regimencomplexity and mortality. The results from this study showed that higher MRCI scoreswere associated with an increase in all-cause mortality over a period of 3years.85 Morecomplex medication regimens with MRCI scores greater than 35 have been shown tobe inversely associated with discharge directly to home from hospital.
86 Inaddition to their association with hospital admissions and mortality, complexmedication regimens also have an impact on patient knowledge of new medicationsadded to their regimens. Newly prescribed medications are common, withan estimated 40% of patients discharged from the emergency department receivingat least one new medication. In patients with already complex regimens, theaddition of another medication to an already complicated list can make it moredifficult to be knowledgeable about their medications.87Becausepoor adherence to therapy has been shown to have a negative effect on patientsand to result in higher medical costs,88 it is important to evaluate impact ofmedication regimen complexity on adherence to medicines.Several studies have examined the relationship between MRCI and adherence. Moczygembaetet al (2012) and Farris et al (2003) did notfind an association between medication regimen complexity and adherence;however, these studies did not present detailed results. Several other studieshave demonstrated that MRCI negatively impacts adherence in older adults.
89,90A study by Vik et al (2006) who assessed theconsequences of medication non-adherence in rural and urban home-care clientsconcluded that medication non-adherence was associated with high drug regimencomplexity scores.6 Another study that quantified medicationregimen complexity in older adults and assessed its impact on health outcomesafter hospital discharge. This study found that higher regimen complexity,assessed using the MRCI, was associated with higher self-reported non-adherenceto medication following discharge. This association persisted for at least onemonth after discharge.56The aim of treatment with medication is tooptimize the benefit from medication while preventing side effects.Unfortunately, this balancing act often requires detailed directions for thepatient, which tends to make treatment plans more complicated. The elderlypopulation generally has more difficulty in adhering to complex treatmentplans.
57Several factors play a role in complicatingmedication regimens. These include the number of medications that need to betaken, the dosing frequency and any additional instructions given by theprescriber.91 These factors all play a part in influencingpatient adherence to treatment, and are therefore important considerations inpromoting good adherence to medication therapy.Several studies have compared simple andcomplex dosing schedules. These studies have shown that adherence to therapy islower with more complex dosing schedules, and that this has a negative impact forpatients.
92 Aretrospective cohort study investigated adherence in patients with type 2diabetes taking oral anti diabetic medications, and reported that complextreatment plans with more frequent dosing schedules were linked with pooradherence to therapy.93 Portsmouth et al (2005) reported that patientson twice-a-day treatment plans had lower adherence over time than those on oncedaily dosing regimens.94The evidence that fewer daily doses areassociated with better adherence is strong and consistent, with this findingcorroborated in several other studies. A study investigating how the frequencyof insulin administration affected adherence found that 79% of patients on atwice-a-day regimen adhered to this schedule, while only 38% of patients takinginsulin three times a day were adherent.95 A study by Dezzi et al (2002) found that type2 diabetic patients taking once-daily glipizide were had better adherence ratesthan patients taking glipizide twice daily, although adherence in both groupswas suboptimal. In this study, patients taking the medication once a day had totake a make sure of the sentences larger number of tablets per dose, so theresults suggest that frequency of dose has a larger impact on adherence thannumber of dosing units.
96 Other studies have also found that once-dailyregimens are associated with better adherence than more frequent dosingschedules what is thiscite 57 97Thrice-daily regimens may be particularlydifficult, with many patients reporting missing the middle dose.98Although it has been established that higherdosing frequency has a negative impact on adherence, other elements ofcomplexity may also impact adherence. Number of medications is negativelyassociated with adherence, and it has been reported that in patients takingthirteen or more medications daily, adherence may be as low as 20%.99 A studyby Paterson et al found that less complicated regimens with fewer doses andlittle or no special instructions (such as food and storage requirements) wereassociated with better adherence.100,101 Anotherstudy investigating the effect of multiple dosage forms showed a 32% adherencerate to treatment regimens with multiple components such as inhaled andsystemic corticosteroids and long-acting bronchodilators in patients withsevere asthma.102