Abstract
In a preoperative anesthesia setting with integrated neuropsychology for individuals >64 years, we completed a pilot study examining the association between neurocognitive disorders with frequency of missed colonoscopies and quality of bowel preparation. Gastroenterologists completed the Boston Bowel Preparation Scale (BBPS) for each patient. Of 47 older adults seen in our service, 68% met criteria for neurocognitive disorders. All individuals failing to attend the colonoscopy procedure had met criteria for major neurocognitive disorder. Poor bowel preparation was also identified in 100% of individuals with major neurocognitive disorder and 28% of individuals with mild neurocognitive disorder. Our pilot data suggest that, in high-risk individuals, the presence of neurocognitive disorders are risk factors for missed appointments and inadequate bowel preparation. These pilot data provide reference statistics for future intervention protocols.
MeSH Keywords: Independent living, dementia, cognition, anesthesia, colorectal, risk factors
INTRODUCTION
Colonoscopies are structural tests used to detect colon abnormalities and remove pre-cancerous polyps to reduce colorectal cancer (CRC) incidence.1 Today, colonoscopies are the most common CRC screening tool in the US with over two-thirds of all procedures performed in adults over the age of 502 and Medicare eligible-individuals.3 Although the United States Preventive Services Task Force (USPSTF) recommends discontinuation of the procedure in adults >75 years, the upper age limit has not been strictly enforced.3, 4
Colonoscopies are accompanied by increased healthcare cost and many individuals scheduled for colonoscopies fail to present for their scheduled appointments.5–7 Missed colonoscopies reduce providers’ revenue opportunities, increasing indirect costs of healthcare, and delay identification and treatment of existing colon abnormalities. In medical centers with limited infrastructure, missed colonoscopies interfere with efficient provision of services and may prolong wait times for appointments.6,7 Patient-related risks revolve around poor bowel preparation (prep). Suboptimal bowel prep can result in premature discontinuation of the procedure, interfere with treatment of existing pathological lesions, and precipitate a repeat colonoscopy thereby usurping valuable financial resources.8–10
Factors associated with failure to attend a scheduled colonoscopy include transportation challenges, scheduling conflicts, and changes in medical status.5,6 Identified risk factors for poor bowel preparation include increased age, male sex, consumption of certain medications, and low health literacy.11,12 Although some report that dementia is a risk factor for suboptimal prep, this has been examined via medical record review and mostly in non-US based samples.12 Research has not investigated if preoperative mild or major neurocognitive disorder13 is a predictor of missed appointments or suboptimal bowel preparation. This is a timely question given the rate of mild neurocognitive disorder in community-dwelling adults14 and cognitive impairment inpreoperative settings.15,16
We examined the rate of cognitive impairment (mild and major) in high-risk individuals presenting for colonoscopies to help inform prospective studies in this area. Risk for Alzheimer’s disease and other related dementias (ADRD) increase steadily after the age of 65 years. As such, we expected to find individuals with cognitive impairment in our sample of older adults presenting for colonoscopies. We evaluated whether the presence of a mild or major neurocognitive disorder would associate with rate of missed colonoscopies and inadequate bowel preparation. Whereas mild neurocognitive disorder is classified as reductions in one or more cognitive domains, major neurocognitive disorder involves limitations in functional independence. We hypothesized that individuals with major neurocognitive cognitive disorder would be more likely to miss their scheduled appointments and have suboptimal bowel preparation.
METHODS
Participants
This study was approved by the University’s Institutional Review Board (IRB # 201800154) and requirement for written informed consent was waived by the IRB. We conducted a retrospective data review of individuals seen from August 7, 2017 to December 20, 2017 as part a preoperative service where licensed neuropsychologists are integrated into older adult patient care. We analyzed medical record data from individuals >64 years old presenting for a pre-procedural workup before their colonoscopies. Adults with learning disorders were excluded from this study due to potential cognitive confounds.
Procedures
Staff within the University of Florida preoperative anesthesia clinic conduct in-person preoperative evaluations for individuals 1) prescribed ≥5 active medications, 2) with a body mass index >40, 3) scheduled for a procedure that may result in a blood loss >500 ml, 4) scheduled for complex and/or high-risk surgical procedures, or 5) expected to receive general or neuraxial anesthesia. Individuals >64 years scheduled for an in-person preoperative anesthesia appointment proceed through several stages of screening for cognitive vulnerabilities:
Stage 1. Preoperative medical staff administer a frailty test, clock drawing test to command and copy condition, and a 3-word memory task.16 Individuals who miss a memory item or produce a clock error complete an immediate neurobehavioral status exam. Stage 2. The neurobehavioral exam begins with a clinical interview wherein a clinical psychologist with neuropsychology specialty and expertise in neurodegenerative disorder, delirium, and pre-postoperative cognitive risk acquires information on developmental/professional histories, previous postoperative outcomes, functional status, changes in cognition and functioning, as well as current health behaviors (e.g., physical activity, sleep hygiene), and also reviews medications anticholinergic medication load. Pain and psychiatric symptoms are assessed using a modified visual analog scale and a 10-point Likert scale, respectively. Stage 3. In the next part of the neurobehavioral exam, trained clinicians administer neuropsychological measures of reading ability, global cognition, attention, working memory, inhibitory functioning, language, visuoconstructional abilities, learning/memory, psychiatric symptoms, and functional status (See Table 1 for a full list of test measures at the time of this evaluation). When possible, raw scores were transformed using available norms and individuals were compared to same-age peers. Stage 4. A licensed neuropsychologist with expertise in neurodegenerative disorders and perioperative cognitive change reviews the patient’s performance, provides feedback, and makes recommendations to the patient and his/her caregiver.
Table 1.
Components of the Perioperative Cognitive Anesthesiology Network (PeCAN) Neurobehavioral Examination at the Time of This Investigation.
| Domain | Instrument (listed alphabetically by domain) |
|---|---|
| Patient and caregiver interviews | Completed by licensed psychologist with neuropsychology specialty |
| Premorbid Functioning Reading Grade Level |
Demographically based index of premorbid intelligence21 Wide Range Achievement Test, 4rd edition (WRAT4) - Reading Subtest22 |
| Global Cognitive Functioning | Clock Drawing to Command and Copy23, Mini-Mental State Exam24 total score |
| Attention | Boston Revision of the Wechsler Memory Scale Mental Control subtest: Months Forward25 Mini Mental State Exam – Three Word Registration24, Wechsler Adult Intelligence Scale, 3rd edition Digit Span Forward20 |
| Working Memory/Inhibitory Functioning | Boston Revision of the Wechsler Memory Scale Mental Control subtest: Months Backward25 Letter Fluency (Letter F)25,26 Mini Mental State Exam sub-item: WORLD spelled backwards24 Wechsler Adult Intelligence Scale, 3rd edition Digit Span Backward20 |
| Language | Animal Fluency27 Mini Mental State Exam language items (repetition, naming, comprehension, writing)24 Test of Reception of Grammar - selected items28 |
| Visuoconstructional abilities | Clock Drawing to Command and Copy23 Mini Mental State Exam Intersecting Pentagons24 |
| Learning and Memory | Hopkins Verbal Learning Test-Revised29 Mini Mental State Exam Orientation Items24 Mini Mental State Exam 3-word Recall24 |
| Affective/Pain | Geriatric Depression Scale30 Likert Scale for anxiety, apathy, depression, fatigue, current pain |
| Functional Status | Instrumental & Basic Activities of Daily Living (completed by caregiver)31 |
| Anticholinergic Medication | Anticholinergic Risk Scale32 |
Components of the protocol administered in the UF Perioperative Cognitive Anesthesia Network at the time of the current investigation.
At the UF Health Shands hospital, gastroenterologists performing colonoscopies are required to enter a Boston Bowel Preparation Scale (BBPS)17 score into the electronic health record at the end of each colonoscopy. BBPS scores range from 0 (suboptimal) to 9 (optimal) for each section of the colon (i.e., right, transverse, left).17
For the current study, two licensed neuropsychologists (SL, CP) reviewed de-identified patient data for mild and major neurocognitive disorders using criteria from the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition)18 criteria. Unspecified psychiatric disorder and somatic disorders were other diagnostic considerations. The licensed neuropsychologists (SL, CP) concurred in their assigned diagnosis over 85% of the time, and interrater reliability was “good” across all diagnoses (κ= 0.79). To resolve discrepancies between clinicians, a postdoctoral clinical neuropsychology fellow (FA) blinded to previous diagnoses, reviewed the chart and assigned a diagnosis. A majority rule approach was applied; if two raters gave a primary diagnosis of mild neurocognitive disorder a diagnosis of mild neurocognitive disorder was assigned. Missed appointments and bowel preparation were assessed in a strategic manner through review of medical record data. BBPS scores of 2 or 3 across all colon segments are needed to detect adenomas larger than 5 mm, and segments with a BBPS score of 1 or less have a higher rate of missed lesions.19 A score of 2 and 3 in any segment of the colon indicated “adequate” bowel prep and a score of <1 in any segment of the colon indicated “inadequate”. Covariates for consideration included the American Society of Anesthesiology (ASA) score and the Charlson Comorbidity Index (CCI).
Statistical Analysis
SPSS version 22.0 (IBM, New York, NY) was used for all statistical analyses. Variables were checked for accuracy and normality. Measures of central tendency were calculated for all demographic, clinical, and cognitive variables. Independent t-tests and Chi-square tests were calculated to compare individuals who did not present for their scheduled colonoscopies versus those who did and to evaluate the adequacy of bowel prep across clinician-rendered diagnosis. Significance was set at .05.
RESULTS
From August 07, 2017 to December 20, 2017, 596 older adults were referred for a neurobehavioral examination with the neuropsychology team. Of those, 53 individuals were scheduled for colonoscopies and six individuals excluded from the current study due to their history of learning disabilities (Figure 1).
Figure 1. Data Collection Procedure and Path to Final Participant Sample-.
*The UF preoperative anesthesia clinic assesses patients who have: 1) 5 or more active medications, 2) body mass index >40, 3) procedure may result in a blood loss >500 ml, 4) complex and/or highrisk surgical procedures, 5) planned general or neuraxial anesthesia.
In total, 47 individuals completed all aspects of their pre-procedural appointment. Table 2 includes the demographic characteristic of the sample. Clinically, of the 47, 13 individuals were frail and 35 individuals had ASA scores ≥ 3. Overall, 38% and 29% of our sample met diagnostic criteria for mild and major neurocognitive disorder, respectively.
Table 2.
Independent Sample t-test of Study Patients versus Patients Who Did Not Present for Their Scheduled Colonoscopy
| Pre-procedural Visit (n=47) | Missed Colonoscopy (n=9) | |
|---|---|---|
| M (SD) or n (%) | M (SD) or n (%) | |
| Demographic Characteristics | ||
| Age | 72.0 (6.6)) | 75.8 (6.6) |
| Education | 12.9 (3.3) | 10.38 (2.8) * |
| Male | 25 (53) | 6 (67) |
| Race | ||
| White | 31 (66) | 5 (56) |
| Black | 14 (30) | 4 (44) |
| Other | 2 (4) | 0 (0) |
| Clinical Characteristics | ||
| Frailty Score ≥333 | 13 (28) | 3 (33) |
| ASA Score ≥3 | 35 (74) | 6 (67) |
| CCI34 | 5.6 (1.6) | 7.3 (1.7) * |
| BMI | 28.8.1 (6.5) | 30.5 (4.5) |
| Current Tobacco Users | 3 (6) | 4 (44) |
| Current Alcohol Users | 13 (28) | 3 (33) |
| Prescribed Opioids | 13 (28) | 3 (33) |
| Cognitive Characteristics | ||
| Mild Neurocognitive Disorder | 18 (38) | -- |
| Major Neurocognitive Disorder | 14 (29) | 9 (100) |
Missing Appointments:
Of the 47 individuals who completed their pre-procedural anesthesia workup, nine did not present for their scheduled colonoscopy (“non-attenders”). Every non-attender had met diagnostic criteria for major neurocognitive disorder at the time of their pre-procedural evaluation at the University of Florida preoperative anesthesia clinic. Relative to people who attended the appointment, non-attenders also had fewer years of formal education (t (44) = −2.1, p = 0.04) and higher Charlson Comorbidity Index scores (t (45) = 2.78, p = .008). Groups did not differ across any other demographic or clinical characteristics (p >.05; See Table 2).
Bowel Preparation:
Of the 38 who did present for the scheduled colonoscopy, 18 and five met diagnostic criteria for mild and major neurocognitive disorder, respectively. Every patient with major neurocognitive disorder who presented for a scheduled colonoscopy had a BBPS<2, indicating inadequate bowel prep. Importantly, five individuals with mild neurocognitive disorder also presented with inadequate bowel prep. Individuals with “adequate” versus “inadequate” bowel preparation did not differ in terms of demographic or clinical characteristics (p’s > 0.05; See Table 3).
Table 3.
Independent Sample t-test Comparing Demographic, Cognitive, and Clinical Characteristics for Patients with/without Adequate Bowel Preparation
| Colonoscopy with BBPS | |||
|---|---|---|---|
| BBPS<2 (n= 12) | |||
| M (SD) or n (%) | M (SD) or n (%) | p-value | |
| Demographic Characteristics | |||
| Age | 72.4 (6.8) | 71.3 (6.4) | 0.65 |
| Education | 13.1 (3.8) | 12.7 (1.8) | 0.62 |
| Male | 13 (50) | 6 (50%) | -- |
| Race | |||
| White | 17 (65) | 9 (75) | -- |
| Black | 8 (31) | 2 (17) | -- |
| Other | 1 (4) | 1 (8) | -- |
| Clinical Characteristics | |||
| Frailty Score ≥333 | 6 (23) | 4 (67) | -- |
| ASA Score ≥3 | 19 (73) | 10 (83) | -- |
| CCI34 | 5.5 (1.7) | 6.0 (1.5) | 0.36 |
| BMI | 29.8 (6.5) | 27.4 (6.5) | 0.28 |
| Current Tobacco Users | 3 (11) | 0 (0) | -- |
| Current Alcohol Users | 8 (31) | 5 (42) | -- |
| Prescribed Opioids | 8 (31) | 6 (50) | -- |
| Neurocognitive Characteristics | |||
| Mild Disorder | 13 (50) | 5 (42) | -- |
| Major Disorder | -- | 5 (42) | -- |
The American Society of Anesthesiology Score (ASA) score ≥3= Elevated risk of poor postoperative outcomes; BBPS= Boston Bowel Preparation Scale (BBPS); All segments ≥2= Adequate; At least 1 segment <2= Inadequate; Body Mass Index (BMI); Charlson Comorbidity Index (CCI)34; Frailty Score33 ≥3= Frail; Given the small sample size, groups were only compared across the continuous variables; M= Mean; SD= Standard deviation.
DISCUSSION
Our findings suggest that, in a sample of high-risk older adult individuals who completed a preoperative workup, moderate to severe cognitive impairment is a risk factor for missed colonoscopy and suboptimal bowel preparation. Each individual failing to attend his/her scheduled colonoscopy had met diagnostic criteria for a major neurocognitive disorder during the in-person preoperative visit. Furthermore, 100% of the individuals who met diagnostic criteria for major neurocognitive disorder at the time of their preoperative workup received a BBPS score of 0 or 1 on at least one segment of the colon. Inadequate bowel preparation was also seen in 28% of individuals with mild neurocognitive disorder. This suggests that even adults with mild cognitive difficulties may struggle to comply with bowel cleansing recommendations.
We recognize study limitations. The design is retrospective and the sample size is small thereby limiting statistical modeling. Although we did not find comorbidity or ASA status to predict bowel preparation quality, we did not systematically assess reasons for referrals or whether individuals received assistance with bowel cleansing recommendations at home. We did not examine the influence of patient-specific characteristics and caregiver involvement in risk of missed appointments and inadequate bowel prep. Given that the study was conducted in a clinical setting, it is unclear if the gastroenterologists reviewed neuropsychological results prior to the completing their BBPS.
In the United States (US), the percent of individuals who present with inadequate bowel prep varies by age, gender, and ethnic-racial group, and rates of inadequate bowel prep range from 15% to 30%. In one study, which examined quality of bowel prep in 3,741 individuals between the ages of 16 to 93 years, Appannagari et al. (2014) found that approximately 33% of adults who completed a colonoscopy between October 2008 and October 2009 presented to their appointment with inadequate bowel prep.20 In our study, 26% of adults who presented for their scheduled appointment had inadequate bowel prep and 100% of them met diagnostic criteria for a mild or a major neurocognitive disorder at the time of their preoperative evaluation. Our study findings indicate that even after completing a preoperative appointment, wherein anesthesia staff reviews procedure-related recommendations with individuals, adults with cognitive impairment may struggle to accurately adhere to recommendations.
There are many study strengths. Our group is the first to examine clinician rendered diagnoses of neurocognitive impairment on colonoscopy appointment arrival and quality of bowel preparation. Pilot findings suggest that even after an in-person preoperative anesthesia visit, adults with cognitive impairment exhibited poor post-procedural outcomes. The study setting was unique and highlights the role of neurobehavioral examination within the preoperative home, even for minimally invasive procedures.
Our findings need validation with prospective investigations that includes less medically compromised individuals, larger sample sizes, and gastroenterologists blinded to cognitive status. Research should also examine whether type of cognitive impairment (i.e., memory only, executive function, language comprehension, etc.) predicts colonoscopy related outcomes. Our pilot data suggest that high-risk individuals presenting for colonoscopy procedures exhibit variability in the cognitive functioning and that those with major neurocognitive disorders are at increased risk for missed appointments and inadequate bowel preparation. We identified an at-risk population that is relatively accessible for future investigations. These pilot data may be used to calculate sample size for prospective investigations and inform the development and evaluation of cost-effective investigations designed to maximize colonoscopy outcomes in older adults with cognitive impairment.
ACKNOWLEDGMENTS
We gratefully acknowledge the Preoperative Anesthesia Center at the UF Health at Shands. Additionally, we thank Dr. Cindy Garvan, Ph.D. and Ms. Allyson Meyer for their technical assistance. We sincerely thank Timothy Morey, M.D., Scott Sumner, MBA, and Glenn Smith, Ph.D., ABPP/CN, for supporting the integration of neuropsychology into a preoperative anesthesia clinic. This work was supported by the National Institutes of Aging (T32-AG04963, Fillingim, FA) and the National Institute of Health (grant no. R01 AG055337, CP/PT; P50AG047266, CP).
Funding: This work was supported by the National Institutes of Aging (grant no. T32-AG04963, FA) and the National Institute of Health (grant no. R01 AG055337, CP/PT; P50AG047266, CP). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Aging or the National Institutes of Health.
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