12.2 CoC Standard 6.5 Follow-Up Rates: Windows, Exclusions & Calculations

The standard, word for word

The 2020 Optimal Resources for Cancer Care standards (updated through October 2025) place follow-up in Chapter 6, Data Surveillance and Systems, as Standard 6.5: Follow-Up of Patients. The measure of compliance has two parts:

1. An 80 percent follow-up rate is maintained for all eligible analytic cases from the most current year of completed cases through 15 years before, or the program's first accreditation date, whichever is shorter.
2. A 90 percent follow-up rate is maintained for all analytic cases diagnosed from the most current year of completed cases through five years before, or the program's first accreditation date, whichever is shorter.

At the site visit, the reviewer looks at the current follow-up report. Programs undergoing their initial accreditation site visit are exempt from Standard 6.5.

Finding the windows

CoC defines the "most current year of completed cases" as cases diagnosed three years before the current calendar year. The standard's own example: in calendar year 2022, the long-term (80%) window is cases diagnosed 2005–2019, and the short-term (90%) window is 2015–2019. Both windows count the ending year, so "15 years" means 15 diagnosis years in total and "five years" means five.

Shorter window rule: if the program was first accredited in, say, 2016, the 80% window in 2026 runs only from 2016 to 2023, because the first accreditation date gives a shorter window than 15 years.

Who is excluded

Standard 6.5 says all reportable cases are followed except:

• Residents of foreign countries.
• Cases reportable by agreement, such as tumor types that the cancer committee or state asks to be collected but CoC does not require.
• Patients whose age exceeds 100 years and who have had no contact for more than 12 months.
• Analytic cases with Class of Case 00.

Nonanalytic cases (Class of Case 30–99) are not in the denominator at all, because the standard applies to analytic cases.

Calculating a follow-up rate

A follow-up rate compares cases with successful follow-up to all eligible cases in the window:

$\text{Follow-up rate} = \frac{\text{eligible cases with successful follow-up}}{\text{all eligible analytic cases in the window}} \times 100$

• Successful follow-up includes patients known to be dead, because the death date and vital status are final, and living patients whose information is current.
• Current: the 2020 standard does not give a day count. Registry software follow-up reports commonly use the convention from earlier CoC standards and treat a living patient as current when the Date of Last Contact is within 15 months of the report date. That allows for an annual cycle plus processing time. Check your software's setting. Patients not current are lost to follow-up in the calculation.
• Always remove exempt cases from both the numerator and the denominator.

Worked example (calendar year 2026)

The 90% window is 2019–2023.

Follow-up rate = 2,050 ÷ 2,260 = 90.7%, which meets the 90% requirement. If 30 more patients became lost to follow-up (2,020 ÷ 2,260 = 89.4%), the program would fall short.

Monitoring unknown values

Standard 6.5 also says the cancer committee monitors the use of unknown values to ensure complete data reporting. This matters most for Date of First Recurrence, Type of First Recurrence and Cancer Status. A registry that codes "99, unknown if recurred" for many patients has technically been followed but provides little outcome value. The standard also expects every CoC program to provide treatment or follow-up information and assistance to referring cancer programs.

Strategies to stay above the thresholds

• Work the 5-year window first, because the 90% threshold is stricter and recent patients are easier to reach.
• Run passive matches before letters: facility encounters, EHR portals, state central registry updates and death-index linkage often make many cases current without any mailing.
• Use the right contact for each patient: the managing oncologist for recent cases, and the primary care physician or the patient for long-term survivors.
• Track lost cases by diagnosis year and investigate spikes, which often come from registry conversions or staff turnover.
• Report the rates to the cancer committee with an action plan when a rate is near the threshold.

Common exam traps

• Standard 6.5 is the follow-up standard; there is no separate "Standard 5.3" follow-up rule in the 2020 standards.
• The windows start at the most current completed year, which is three years before the current year, not the current year.
• Dead patients count as successfully followed.
• Class of Case 00 patients are analytic but are excluded from follow-up.