Are High-Risk Drugs More Safely Prescribed in Certain Areas?

A new report published in the New England Journal of Medicine reveals significant geographic variations in terms of medication errors and appropriate drug prescribing, particularly for elderly patients.

Even after adjusting for variation in demographic characteristics, individual health status, and insurance coverage, lead author Yuting Zhang, PhD, of the University of Pittsburgh, and colleagues found that Medicare spending on pharmaceuticals differs substantially among US localities and hospital-referral regions.

In their assessment of geographic variation in the management of medication in the elderly, Zhang and colleagues used two quality measures from the Healthcare Effectiveness Data and Information Set (HEDIS) to assess whether Medicare beneficiaries:

• Received at least one drug that should be avoided in the elderly—including some antihistamines, long-acting benzodiazepines, thioridazine, and some skeletal muscle relaxants;
• And those with evidence of dementia, a history of hip or pelvic fracture, or chronic renal failure are given a prescription in an ambulatory care setting that is contraindicated for that condition.

The investigators used pharmacy and medical claims data from a random sample of 5% of Medicare beneficiaries who were enrolled in stand-alone Medicare Part D plans in 2007. Each person in the resulting sample of 533,170 beneficiaries was assigned to one of the 306 Dartmouth hospital-referral regions on the basis of the ZIP Code of residence.

To determine the amount of variation in the use of high-risk medications, Zhang and colleagues calculated the proportion of beneficiaries in each hospital-referral region who had received at least one high-risk drug in 2007. They assessed the potentially harmful drug-disease interactions for each of the three conditions separately and used a combination measure indicating the proportion of patients with at least one of the three conditions who were taking any potentially harmful drug. They then calculated the proportion of beneficiaries with dementia in each hospital-referral region who had received a potentially harmful drug in 2007.

The three key messages from the analysis, they wrote, are as follows:

1. Hospital-referral regions vary substantially in terms of HEDIS measures of the quality of prescribing. Performance on these measures varies considerably more than spending does, whether variation is measured in terms of the coefficient of variation or the ratio of spending at the 75th percentile to that at the 25th percentile. The hospital-referral region with the largest proportion of elderly beneficiaries taking high-risk drugs is Alexandria, LA, where 44% of elderly beneficiaries received them—which is significantly higher than the 11% who received them in the Bronx, NY, the best-performing hospital-referral region on this measure.
2. After adjustment for demographic variables and level of health risk, performance on the two measures was positively but very weakly related to overall drug spending. Regions in which beneficiaries were more likely to be given prescriptions for potentially harmful or high-risk drugs did not necessarily spend more on drugs overall than regions in which beneficiaries were less likely to use such drugs.
3. Both markers of low-quality prescribing were positively associated with higher medical spending, excluding drug spending. The regions in which nondrug medical spending per beneficiary was higher were also the regions in which beneficiaries were more likely to be given prescriptions for potentially harmful or high-risk drugs—a finding that does not support the premise that higher medical spending leads to higher-quality prescription use.

In conclusion, according to HEDIS measures of potentially dangerous prescribing patterns, the quality of prescribing for the elderly varies substantially among local markets—substantially more, in fact, than does spending on drugs overall. These results do not support the theory that high-spending areas simply use more of everything, including inappropriate drugs, since the association between overall drug spending and inappropriate prescribing is weak. In addition, because spending on nondrug medical care is positively associated with a greater use of potentially harmful drugs, these findings also do not suggest that more medical spending is associated with better health care overall. These results are consistent, however, with an association between lower-quality prescription patterns and more adverse drug events that may require additional expense to treat.

To access the report, click here.

Are you surprised that the study found that higher medical spending does not necessarily lead result in better care overall? What implications do these findings have in terms of health care reform?