HSR&D Home » Research » IIR 08-334 – HSR&D Study
Determinants of Timely Evaluation Colonoscopy for crc Screening Tests
Melissa R. Partin, PhD
Minneapolis VA Health Care System, Minneapolis, MN
Funding Period: March 2010 - February 2013
Fecal Occult Blood Testing (FOBT), one of the most common colorectal cancer screening modes employed by the Veterans Health Administration (VHA), can be a highly efficacious screening method if positive results are followed by complete diagnostic evaluation (i.e., diagnostic colonoscopy). However, significant gaps in complete diagnostic evaluation (CDE) rates have been identified in several prior VHA studies documenting that at best 50% of veterans with an FOBT positive (FOBT+) result receive CDE. This study was designed to inform future colorectal cancer diagnosis quality improvement efforts by providing information on the patterns and correlates of CDE.
Study objectives included: (1) estimating the effects of organizational structures, clinic processes, and individual factors on CDE rates; (2) estimating the sensitivity of CDE rate estimates to assumptions about patient refusal, private sector CDE, and inappropriate FOBT use (i.e., FOBT in patients age less than 45 or older than age 85; who had a colonoscopy within the past 10 years; or with limited life expectancy); and (3) estimating the fraction of CDE delay due to time from FOBT+ to CDE scheduling, versus time from CDE scheduling to CDE completion. We hypothesized that higher CDE rates would be associated with clinic processes that: (H1) control colonoscopy appointment requests (e.g., clinical reminders and consult templates that ask about contraindications; evidence-based surveillance practices); (H2) employ lean thinking principles (e.g., direct notification of gastroenterology providers of FOBT+ results); and (H3) address patient barriers (e.g., clinic initiated scheduling; negotiating appointment times with patients; patient reminders; verbal preparation instruction).
The sampling frame for this three-year observational study was VHA facilities that conducted at least 1,400 FOBTs in 2009. Data collection activities included: (1) a web-based survey at the 125 VHA facilities in the sampling frame, completed by the Chiefs of Primary Care (73% response rate) and Gastroenterology (81% response rate) to assess CDE related organizational structures and clinic processes; (2) VHA administrative data extraction from each facility on FOBT+ cases occurring between 8/16/09 and 3/20/11, and colonoscopies completed between 8/16/09 and 9/20/11 to assess if and when a colonoscopy appointment was scheduled, cancelled, and completed, if applicable, and to gather patient demographic and health characteristics, and (3) administrative data extraction, manual chart review, and text mining to estimate rates of refusal, private sector CDE, and inappropriate FOBT utilization among FOBT+ patients not receiving CDE in the VHA within 6 months. The primary outcome measures included: the proportion of FOBT+ completing CDE in the VHA within 60 days and 6 months. The primary analyses estimated the association between these outcomes and measures of organizational structures, clinical processes, and individual factors using hierarchical logistic regression analyses incorporating random effects for facilities of care, and employing common model development processes to arrive at a final predictive model for each outcome.
We identified 86,926 unique individuals with FOBT+ results between 8/16/09 and 3/20/11 at the 125 sampled VHA facilities. Overall, 31% of FOBT+ cases received CDE at a VHA facility within 60 days (range 10-57% across facilities, p-value less than .0001) and 49% received CDE at a VHA facility within 6 months (range 28-70% across facilities, p-value less than .0001). The average number of days to CDE among FOBT+ cases receiving CDE at a VHA facility within 6 months was 60 (range 32-95 across facilities, p-value less than .0001).
Our chart review and text mining exercises estimated that 55-68% of FOBT+ cases that did not receive CDE in the VHA within 6 months had one or more valid reasons, including: CDE refusal (13-18%), pursuing CDE in the private sector (9-14%), inappropriate FOBT (28-31%), and death within 6 months (5%). If refusals and private sector CDE are considered adequately followed up, and deaths and inappropriate FOBT are excluded, the 6 month CDE rate estimates would range from 67-77% (a 19 to 29 percentage point increase above the original estimate of 48%).
Patient subgroups least likely to receive CDE at a VHA facility within 6 months included: veterans age 65 and older (16% for those 85 and older, 40% for those 65-84, versus 55% for those age 50-64, p-value less than .0001); widowed veterans (40%, versus 46% for married and 51% for unmarried, p-value less than .0001); and those with greater comorbidity (43% for Charlson scores 1 standard deviation above the mean, versus 52% for those with scores 1 standard deviation below the mean, p-value less than .0001).
Predictive models estimating the association between organizational structures, clinic processes and CDE rates provided partial support for our hypotheses. With respect to H1, using guideline concordant colonoscopy surveillance practices (7-10 versus less than 5 year repeat colonoscopy window for cases with 1-2 small adenomas) was positively associated with 6 month CDE rates (OR 1.54 p=0.02). With respect to H2, FOBT+ notification systems that relied on lab or gastroenterology rather than primary care staff were positively associated with both 60 day (OR 1.85, p=0.01) and 6 month (OR 1.26, p=0.01) CDE rates. Counter to H3, clinic initiated scheduling, negotiated appointments, patient reminders, and verbal preparation instructions were not significantly associated with CDE rates.
Analyses based on the 64,066 FOBT+ cases with complete and reliable appointment data revealed that 66% of FOBT+ cases that did not complete CDE within 6 months never had an appointment scheduled in a clinic that performs colonoscopy. Among the FOBT+ cases that did complete a CDE within 6 months, the average number of days between FOBT+ and scheduling of the first appointment in a colonoscopy clinic was 23 (range 5-50 across facilities, p-value less than.0001), and the average number of days between scheduling the first appointment in a colonoscopy clinic and CDE completion was 39 (range 14 - 62 across facilities, p-value less than.0001).
Although CDE rates are likely considerably higher than VHA administrative data sources suggest, room for improvement in the follow-up of FOBT+ results within VHA remains. Our findings suggest improvements in CDE rates within the VHA may be facilitated by enhancing the guideline consistency of colonoscopy surveillance practices, and transferring responsibility for identifying FOBT+ cases from primary care to lab or gastroenterology staff.
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NIH ReporterGrant Number: I01HX000122-01
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DRA: Health Systems, Cancer
Keywords: Cancer, Quality assessment, Screening
MeSH Terms: none