Patient-Centered Guidelines for Geriatric Diabetes Care: Potential Missed Opportunities to Avoid Harm

Ellen M. McCreedy, PhD; Robert L. Kane, MD; Sarah E. Gollust, PhD; Nathan D. Shippee, PhD; Kirby D. Clark, MD


J Am Board Fam Med. 2018;31(2):178-180. 

In This Article


The ADA guidelines for older adults[6] recommend HbA1c targets <7.5% for older adults with few comorbid conditions and intact cognitive and physical functioning, and targets <8% for older adults with comorbid chronic diseases, impaired IADLs, or mild to moderate cognitive impairment. In this vignette-based study, we observed appropriately high rates of treatment intensification for relatively younger patients with few comorbid conditions and intact physical and cognitive function. For otherwise healthy older adults, the mean predicted probability of treatment intensification was 73% (95% CI, 67–78%) at an HbA1c of 7.5% and was 95% (95% CI, 93–97%) at an HbA1c of 8.5. However, we also detected potential missed opportunities to provide guideline-consistent care for older patients with comorbid cognitive impairment. An 80-year-old woman with long-standing diabetes, coronary artery disease, and cognitive impairment with associated IADL impairment had a mean predicted probability of treatment intensification of 35% (95% CI, 29–41%) at an HbA1c of 7.5%, despite the fact that the guidelines suggest an appropriate HbA1c target <8%.

Contrary to expectations, preexisting cardiac complications did not decrease the likelihood that clinicians would intensify treatment in this study. Post hoc analyses of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial and the Veteran's Affairs Diabetes Trial (VADT) suggest that tight glycemic control may confer additional risk of death for people with preexisting cardiovascular risk with long-standing diabetes.[9,10] More research is needed to understand why the presence of coexisting coronary artery disease, which is specifically mentioned in existing guidelines, did not affect clinician behavior in the current study.

Our findings also hint at differences in treatment intensification by clinician type and/or by state. Overall, FM physicians were about 8 percentage points less likely than IM physicians and NPs to intensify glycemic medications. This is after controlling for a large, state-level difference in intensification between Florida and other states involved in the study (mainly Minnesota and Wisconsin). As the geriatric population continues to grow and the primary care workforce shortage deepens, the need increases for evaluation of practice patterns and patient outcomes associated with clinician type.[11] Given the dramatic increase in the number of Medicare beneficiaries treated by NPs,[12] and given that Florida is second only to California in the number of Medicare beneficiaries, additional research is warranted to disentangle training and state effects. If clinician-type differences are replicated, policy and workforce deployment strategies may look to family medicine training programs to identify and leverage factors that promote individualized care for older adults with multiple chronic conditions.

Given the convenience nature of the sample and the low response rates, we have to be careful when interpreting and generalizing findings. In particular, we need to consider the effects of nonresponse error and coverage bias. Nonresponse error occurs when people who respond to the survey are different from those who do not respond. Clinicians who provide accurate e-mail addresses during licensure are likely different from those who do not, and clinicians who respond to unsolicited e-mails to complete surveys without a financial incentive are different from those who do not. We suspect that clinicians attending a regional conference, participating in PBRNs, or responding to an unsolicited request for help with a survey about diabetes care may be more familiar with the existing patient-centered guidelines than other clinicians. If this is the case, our estimates of potential overtreatment, or missed opportunities to follow existing recommendations for older adults, may be conservative. We also have some coverage bias. With the licensure lists, we started out with e-mails for approximately 60% of licensed primary care clinicians in Florida and Minnesota. However, 5% to 10% of these E-mails were not active, and we were unable to estimate the percentage of remaining e-mails that were actually monitored (vs "junk e-mails"). Therefore, caution should be used when generalizing these findings to the population of all licensed primary care clinicians in those states or to all clinicians of a certain discipline.

However, with those generalizability caveats, vignette studies have been shown to be good predictors of how clinicians will behave in clinical settings.[13] By systematically varying factors in existing guidelines, factorial vignette surveys are a cost-effective way to broadly understand practice patterns and compliance with quality initiatives. Our estimates of potential missed opportunities are closely aligned with recent survey results revealing that one third of primary care clinicians thought it would be difficult to follow the Choosing Wisely HbA1c recommendation for older adults, which asks clinicians to "Avoid using medications other than metformin to achieve hemoglobin A1c <7.5% in most older adults."[14] As part of the same study, clinicians reported existing pay-for-performance (P4P) initiatives tied to lower HbA1c levels and fear of potential litigation as reasons they may not reduce medication burden as a person develops additional comorbid complications that limit life expectancy.[14] P4P or pay-for-quality incentives rewarding intermediate outcomes (HbA1c levels) below a certain threshold (eg, <8%) are widespread.[15,16] Policy options to address overtreatment include incentives to appropriately deintensify treatment[17] or to decrease rates of hypoglycemia.[18] It is important that we align incentives to provide appropriate care throughout the implementation and evaluation of the Merit-Based Incentive Payment System.[19]

Finally, our study shows that 59% of the variation in the decision to intensify medication therapy was not related to the factors mentioned in the existing patient-centered guidelines (age, disease duration, cognitive impairment, and cardiac complications) or to the clinician factors we measured. We are left to speculate as to the other factors affecting primary care clinicians' decisions to intensify glycemic medication therapy. In addition to P4P incentives, these "other factors" likely include the influence of training/mentorship,[20] environmental or regional variation in medication use (we found some evidence of state variation in the current study),[21] influence of drug companies on individuals,[22,23] or habitual prescribing behavior.[24] These factors are likely to affect the degree of success we have implementing current (or future) guidelines and therefore deserve careful consideration and more research.

Our findings add to an important and growing body of evidence of missed opportunities to consider comorbid conditions indicating higher glycemic targets in order to avoid known harms.[1,4,14,25–28] In addition, factorial vignettes may serve as a tool for identifying and providing feedback to individual clinicians and health care systems regarding the (under)value placed on individualized, patient-centered care. Future research should further investigate the process and influences on clinician decision making regarding individualizing glucose targets for high-risk geriatric patients, including the influence of training and practice environment. The policy implications are substantial, including the construction of performance incentives, quality reporting, and primary care workforce recommendations.