New Scale Measures Complication Risks for COPD Patients

Ian Stiell, MD, MSc

Physicians may be able to predict with unprecedented accuracy which patients with chronic obstructive pulmonary disease (COPD) are at risk for serious complications with a simple 10-question scale, according to a new study.

Previous studies from Ian Stiell, MD, MSc, and his team at the Ottawa Hospital research institute have shown that half of all Canadian patients with COPD who suffer from serious adverse events do so after being discharged home. The even-split odds can make it difficult for physician to distinguish who would benefit from hospital admission, and who would not.

“Before this tool, there was no way to know if a patient who came to the emergency department with a COPD flare-up was going to have serious complications,” Stiell said in a statement. “This new information can help doctors decide whether to admit a patient or send them home.”

The group developed the Ottawa COPD Risk Scale (OCRS) that doctors can use to screen patients for the likelihood of complications from COPD over the course of 30 days before deciding whether to admit them to the hospital or send them home.

The scale features 10 questions, each assigned 1-3 points for each “yes” answer. The questions pertain to the patients’ medical history and the results of routine tests conducted when they arrive in the emergency room. Some of the measurements included in the questions are heartrate upon arrival, acute ischemic changes on echocardiograms, and hemoglobin levels.

Investigators then tested the scale on 1415 patients in 6 Canadian hospitals who had symptoms consistent with exacerbation of COPD, between May 2011 and December 2013. They then followed those patients’ records for 30 days, taking note of any serious short-term outcomes such as admission to monitored unit, intubation, noninvasive ventilation, myocardial infarction (MI), or relapse with hospital admission within 14 days, or death from any cause within 30 days.

The investigators compared these outcomes to how the patients fared on the scale.

636 patients were admitted to the hospital on their initial visit, while 779 were not. 135 patients experience serious short-term outcomes, 65 of which had not been admitted to the hospital during their initial visit. This is a “concerning portion” of patients, investigators noted.

Higher scores on the scale coincided with increased likelihood of experiencing a serious event. According to the scale, patients who scored one point were at a 4% risk of adverse event, while those that scored 10 (out of 16 total,) were at a 91.4% risk of complications.

If doctors admitted everyone who scored 1 point or higher to the hospital, they’d be 50% more likely than they are now to admit the patients who were most at risk for complications, but they’d have to admit 25% more patients overall. Using 2 points as a benchmark instead of 1 would improve sensitivity compared to current rates by 38% with a very small increase in the number of hospital admissions.

The authors did not specify a precise score that should be considered a cutoff for hospital admission but stressed that the scale could be used in conjunction with other important considerations, such as whether or not a patient has support at home.

“There’s no question that this tool can be used today,” Stiell said. “While designed for emergency physicians, it could also help others who serve patients with COPD, including respirologists, general internists and family doctors.”

The study, “Clinical validation of a risk scale for serious outcomes among patients with chronic obstructive pulmonary disease managed in the emergency department,” was published online in the Canadian Medical Association Journal.