Blog | Wednesday, January 12, 2011

QD: News Every Day--Drug adherence can save patients thousands in later acute care

Patients who follow their prescribed medications for chronic diseases spend far less on later acute care, reports a study.

Economists at a pharmacy benefits management company conducted the study, which was funded by that company. Results appeared in Health Affairs.

Medicine Cabinet by somegeekintn via FlickrMedication adherence has been associated with less acute and emergency care, but this study attempted to establish causality. While the literature is rife with observational studies, they suffer from endogeneity, defined as when a trait is related to both the variable being examined and the outcome being examined. To take a whack at causality, the economists mathematically eliminated unmeasured confounding variables if they did not change over time.

Almost half of all Americans, approximately 133 million people, have at least one chronic disease. The World Health Organization reports average medication compliance of just 50% in developed nations.

The literature shows drug compliance lowers the costs of hospitalizations, with the exceptions of depression, osteoporosis and asthma, in which the more expensive brand-name drugs dominate the market.

So, economists at the pharmacy benefit management company extracted from its database claims data from on 135,000 people who had continuous health insurance coverage through one of nine employers from Jan. 1, 2005, through June 30, 2008. Four cohorts included 16,353 patients with congestive heart failure, 112,757 with hypertension, 42,080 with diabetes, and 53,041 with dyslipidemia.

Outcomes included annual numbers of inpatient hospital days, emergency department visits, and outpatient physician visits, as well as annual pharmacy, medical, and total health care costs.

Adherence was associated with significantly lower annual inpatient hospital days, ranging from 1.18 fewer days for dyslipidemia to 5.72 fewer days for congestive heart failure. Annual emergency department visits were between 0.01 and 0.04 visits per patient per year among adherent patients. Perhaps at the crux of the matter, adherent patients visited their doctors more often than their nonadherent peers did.

Yes, pharmaceutical compliance increased spending on drugs. The average annual pharmacy spending of adherent patients was $1,058 more for those with congestive heart failure, $429 for hypertension, $656 for diabetes, and $601 for dyslipidemia. But adherence reduced average annual medical spending by $8,881 in congestive heart failure, $4,337 in hypertension, $4,413 in diabetes, and $1,860 in dyslipidemia.

The savings for patients was also notable. Annual per person savings were $7,823 for congestive heart failure, $3,908 for hypertension, $3,756 for diabetes, and $1,258 for dyslipidemia.

After combining more pharmacy spending with decreased medical spending, average benefit-cost ratios were 8.4:1 for congestive heart failure, 10.1:1 for hypertension, 6.7:1 for diabetes, and 3.1:1 for dyslipidemia. Effects were even greater for seniors, who saw benefit-cost ratios of 8.6:1 for congestive heart failure, 13.5:1 for hypertension, 8.6:1 for diabetes, and 3.8:1 for dyslipidemia.

While the study itself didn't consider reasons why patients don’t comply with their medications, there are often legitimate barriers. Consider results from one study that concluded that age, stroke-related disability, and several other factors indicate whether a patient will continue adhering to discharge medications three months after a stroke. Race should also be in the back of an internist's mind, although the individual patient's presentation is still the guiding factor.

To make compliance easier, first consider reasons for the noncompliance, advise internists, and then apply strategies that work: simplify, explain and involve.