Routine, PreoOp Testing Costlier for Medicare Than Previously Thought

The traditional 30-day window prior to the date of surgery does not always capture routine preoperative medical testing that occurs when surgery is first contemplated. When considering Medicare patients whose surgery occurs more than 30 days after initially contemplated, routine preoperative medical testing is more prevalent and more costly than previously reported, according to a study published Jan. 18 in JAMA Ophthalmology. This study was limited to cataract surgery, but the findings likely applicable for other ambulatory procedures, the authors say.

"Prior studies on routine preoperative testing, which usually highlight the testing that occurs during a 30-day preoperative window, have not accounted for the extended preoperative testing period that begins when the decision is first made to operate," write the authors led by Catherine Chen, M.D., from University of California, San Francisco. "There are likely to be more patients undergoing routine preoperative testing before low-risk surgical procedures similar to cataract surgery than previously recognized, despite the existence of guidelines recommending against such interventions."

The researchers assessed preoperative care in a sample of 440,857 Medicare beneficiaries (mean age, 7.1 years) who underwent ambulatory cataract surgery in 2011. Ocular biometry, a diagnostic test to determine the required power of the intraocular lens to be implanted during cataract surgery, was the procedure-specific indicator to mark the extended preoperative testing period. The testing rates in the interval between ocular biometry and cataract surgery and compared to testing rates in the 6 months preceding biometry.

Identified laboratory tests that are commonly performed for preoperative workup in older patients, included chemistry panels, complete blood counts, coagulation panels, and urinalysis. (Other included non-laboratory tests included electrocardiography, echocardiography, cardiac stress test, chest radiograph, and pulmonary function tests.)

The researchers found that 96.1 percent of patients had an ocular biometry claim before index surgery. In 6.3 percent the biometry claim was on the day of surgery, 25.4 percent had the biometry claim more than 30 days before surgery, and 5.1 percent had the biometry claim more than 90 days before surgery.

More than 1 million tests were performed during the extended preoperative interval between biometry and surgery. Routine preoperative testing rates were higher during the time interval between biometry and surgery (1.7 tests/patient/month) versus the baseline time period (1.1 tests/patient/ month) or in the months following cataract surgery (1.1 tests/patient/month). Preoperative testing peaked both in the 30 days after biometry (1.7 tests/ patient/month) or the 30 days before surgery (1.8 tests/patient/month).

For patients with the longest preoperative window—patients who had surgery either 6 months or 9 months after biometry—an increase in testing was seen both in the month immediately after biometry (2.4 and 2.6 tests/patient/ month, respectively) and another increase during the month before surgery (2.2 and 2.3 tests/patient/month, respectively) compared with the baseline rate of testing (1.3 tests/patient/month in both cohorts).

Extrapolating the findings for the total Medicare population undergoing cataract surgery in 2011, the total number of routine preoperative tests that were performed during the extended preoperative interval between biometry and surgery cost approximately $45.4 million annually.

"Even when taking into account background testing that may occur in this older population, we showed that the cost of testing increased by 37% over a comparable period that occurred 1 year prior to the biometry claim, suggesting that much of the additional testing that occurred in these patients was in anticipation of undergoing low-risk elective surgery," conclude Chen and colleagues. "As a cost-cutting measure, routine preoperative medical testing should be avoided in patients with cataracts throughout the interval between ocular biometry and cataract surgery."

Takeaway: When accounting for a sizable portion of Medicare patients who undergo cataract surgery more than 30 days after initially consulting a doctor, routine preoperative testing rates are higher than previously estimated. These findings indicate that routine preoperative is common and likely unnecessary among most cataract patients.