Study validates continuity of care clinical measure

A recent study investigating the reliability of a continuity of care quality measure found that it “meets or exceeds acceptable criteria” to be implemented in primary care practices, according to researchers.

Mingliang Dai, MS, PhD, a health services researcher with the American Board of Family Medicine, and colleagues wrote in Annals of Family Medicine that continuity of care (CoC) has a foundational role in the relationship between physician and patient, and more must be done to operationalize it as a clinical quality measure.

So, as part of the Measures That Matter to Primary Care initiative, the American Board of Family Medicine developed a primary care CoC measure “to address the lack of clinical quality measurement ... and to promote CoC as a quality indicator for primary care physicians.”

“CoC is a central tenet of primary care and is associated with fewer hospitalizations and emergency department (ED) visits, better patterns of care utilization, lower costs for patients with chronic conditions and residents of long-term care facilities, and lower mortality,” Dai and colleagues wrote.

The researchers tested the validity and reliability of the CoC measure by calculating the Bice-Boxerman Continuity of Care Index (BBI) for 5.4 million patients with claims data for the 12-month period from July 1, 2018, to June 30, 2019. They “rolled up” the CoC Index “to create an aggregate, physician-level CoC score.” The analysis included 555,213 physicians.

The researchers explained that they opted to use the BBI since it does not require patients to be attributed to a specific PCP, it has previously been used to study CoC in primary care and “it appears in a measure previously endorsed by the [National Quality Forum], which signals organization’s belief in its validity.”

“The BBI attempts to capture the dispersion of visits across a set of physicians for individual patients rather than the aggregate population,” they wrote. “That is, instead of just considering the percent of visits with an attributed PCP, the measure considers how many different PCPs were seen and how many times each was seen.”

Dai and colleagues also noted that they had to figure out how to consider patient-level CoC from the physician perspective to create a physician-based quality measure.

“Whereas there is no standard for what constitutes high or low continuity, research has shown that patients with a BBI 0.7 often experience better outcomes. Therefore, we considered 0.7 a reasonable threshold for patient-level CoC,” they wrote.

They then calculated the physician-level quality measure as “the number of patients seen who have a CoC of 0.7 divided by the total number of patients seen by that physician.” For example, if a physician saw eight patients and five had a CoC of 0.7 or greater, the physician’s performance was estimated to be 62.5%.

In validity tests using the 0.7 threshold patient-level, Dai and colleagues reported that the CoC measure was significantly associated with decreased odds of having more than one ED visit (adjusted OR = 0.718).

“The results of reliability testing suggest that the measure meets or exceeds acceptable criteria, based on the majority of reliability scores >0.7,” the researchers wrote.

Mean performance on the measure, the researchers found, was 27.6%, which means more than a quarter of the patient panels for these physicians reached the target continuity score. However, they also noted that the SD was 30.6%, which suggests wide variability when it comes to physician performance.

Additionally, the researchers found that more than a quarter of physicians “had the worst possible score for continuity” because the 25th percentile was 0%. But the 75th percentile was 50% and the maximum score was 100%, “suggesting significant spread in physician performance.”

Finding a “significant negative association” between the percentage of patients with any ED visits and physician-level continuity, the researchers wrote, indicates “empirical validity and utility of this measure.”

“The CoC quality measure and the research surrounding it should be a signal to practices and health systems that care continuity is important and should be complementary to efforts to improve access to care,” the researchers wrote. “Studies have repeatedly shown that high levels of CoC in primary care are associated with lower care utilization and costs and are preferred by patients and clinicians. Without this measure, access trumps continuity because it also aligns with practice efficiency; a highly valued continuity measure could help balance this tension and drive different appointment and practice strategies.”

Dai and colleagues concluded that “continuity is associated with desirable health and cost outcomes as well as patient preference.”

“The CoC clinical quality measure meets validity and reliability requirements for implementation in primary care payment and accountability,” they wrote. “Care continuity is important and complementary to access to care, and prioritizing this measure could help shift physician and health system behavior to support continuity.”