“Sludge Audits” Identify Obstacles to Completing Colorectal Cancer Screening

Kenny Lin, MD, MPH
Posted on March 10, 2025

In a traditional health care setting, many administrative burdens and barriers stand in the way of patients receiving evidence-based care. Paperwork required to sign up for health insurance and to establish care with a practice. Calling to schedule the next available appointment and taking time off work. Travel to the doctor’s office. Wait times. More travel to a laboratory or a different office for a test or procedure. Remembering to eat or not eat, or what to eat, before being tested. The list goes on.

A 2022 article in the Harvard Business Review introduced the term sludge to describe “these types of situations in which the design of a specific process consistently impedes individuals from completing their intended action.” A sludge audit is “a systematic approach to identifying the presence and cost of sludge and figuring out how to eliminate it.” Although not originally applied to health care processes, sludge audits can improve the efficiency of health systems and patients’ experiences. The article identified four approaches to reduce sludge: (1) reduce the number of steps, (2) add a digital option, (3) remove roadblocks, (4) offer virtual alternatives to in-person processes.

Dr. Michelle Rockwell and colleagues at the Carilion Clinic in Roanoke, Virginia, performed a sludge audit of their colorectal cancer (CRC) screening services in 2021 and 2022. They quantified time, paperwork, communication, technology (number of mouse clicks to order a CRC screening test), other administrative tasks, and low-value CRC screenings. They found that clinicians needed a median of 17 mouse clicks to order a screening colonoscopy; the median wait time between primary care referral and scheduling was more than 6 weeks; wait time between scheduling and having the procedure was more than 6 months; some patients were asked to attend multiple preoperative visits; and nearly 1 in 3 follow-up colonoscopies was judged as being performed at a shorter interval than necessary. Finally, neither patients nor primary care clinicians could easily access the results of colonoscopies or stool-based tests.

Unsurprisingly, patients’ experiences with the health system’s CRC screening process were suboptimal; 37% of surveyed patients reported that their tests were delayed or not done because of “excessive or unnecessary paperwork, communication, technology or waiting.” Patients who chose fecal immunochemical tests needed to visit another location to pick up test kits, and some stated that they could not understand the instructions with the tests. Patients with Medicaid insurance or dual Medicare-Medicare coverage were more likely than those with private insurance to report sludge. In contrast, patients who reported no or minimal sludge were more likely to complete screenings and less likely to report distrust in the health system.

Even in a population where everyone has the same health insurance, having more social needs is associated with lower CRC screening rates. A cross-sectional study of Kaiser Permanente patients ages 50 to 75 years who completed a social needs survey in 2020 found that those who reported severe financial strain, severe social isolation, and severe food insecurity were statistically twice as likely to not be up to date on CRC screening than other patients.