Modifiable factors including weekend consultations are major contributors to inpatient colonoscopy delays

Abstract

BACKGROUND

In value-based care, identifying modifiable “logistical delays“ is important for reducing hospital length of stay (LOS). While clinical factors such as bowel preparation are well established as contributors to inpatient colonoscopy delays, logistical factors, such as the “weekend effect”, are not as well studied.

AIM

To identify logistical and/or modifiable causes of delayed colonoscopies and their impact on LOS.

METHODS

This is a retrospective single-center cohort study of all inpatients who underwent colonoscopy at a single center over a 15-month period. “Delay“ was defined as > 1 calendar day from gastrointestinal (GI) consult signature to procedure for Sunday-Thursday consultations, > 2 days for Saturday consultations, and > 3 days for Friday consultations. Factors predictive of delay and LOS were analyzed using pre-specified logistic and negative binomial regression.

RESULTS

A total of 771 inpatient colonoscopies were included, with 302 (39.2%) delayed. Of these, 65.6% had only clinical delays, 14.9% had only logistical delays, and 19.5% had both clinical and logistical delays. One major logistical factor was weekend scheduling issues. Colonoscopies with consult notes signed on the weekend were associated with increased odds of delay [odds ratio (OR) = 1.66; 95%CI: 1.16-2.37]. Other predictors of delay included non-GI admissions (OR = 3.78; 95%CI: 1.92-7.52) and having both non-GI and GI admission indications (OR = 1.69; 95%CI: 1.22-2.34). Delayed colonoscopies overall were associated with significantly longer LOS [13.4 days (95%CI: 11.5-15.6) vs 9.5 days (95%CI: 8.1-11.0)].

CONCLUSION

Weekend scheduling issues are a significant contributor to inpatient colonoscopy delay. While clinical delays are often unavoidable, logistical delays highlight systemic bottlenecks that are associated with extended LOS.

Key Words: Inpatients; Colonoscopy; Length of stay; Endoscopy; After-hours care; Value-based health care

Core Tip: While clinical factors are known to delay inpatient colonoscopies, the impact of modifiable logistical factors is often underestimated. This study demonstrates that 39.2% of all delays have a logistical component, with weekend consultation being a dominant driver. Consultations initiated on Saturdays or Sundays were associated with 1.7 times increased odds of delay, and procedural delay was in turn associated with an increase in hospital length of stay by an average of 3.9 days. These findings suggest that establishing dedicated weekend endoscopy scheduling capacity and increasing weekend resource allocation to increase staffing offer an opportunity to improve patient care and hospital efficiency.

INTRODUCTION

The shift towards value-based care has highlighted the need to identify and correct modifiable factors leading to delays in care and increasing length of stay (LOS). In the United States, inpatient colonoscopy is typically performed for gastrointestinal (GI) bleeding, but up to 35% of inpatient colonoscopies are performed for other clinical indications including chronic diarrhea, malignancy screening with red flag symptoms, suspicion for inflammatory bowel disease, or expedited workup for patients unlikely to follow up with outpatient colonoscopies, though procedures for these indications are generally less urgently prioritized over GI bleeds[1-4]. Delays in inpatient colonoscopies are not necessarily failures to respond to clinical urgencies but rather a deviation from the expected operational timeline for a procedure in an already-hospitalized patient. Given that these patients are hospitalized, even non-urgent colonoscopies carry implicit time pressure as each additional day of waiting directly extends LOS and its associated costs and risks, and it is recommended to perform non-urgent inpatient colonoscopies at the next available opportunity to reduce LOS[4,5]. While inpatient gastrointestinal endoscopy delays are commonly identified, it is unclear what proportion of these delays are modifiable. Though some delays are inherent to underlying clinical factors (e.g., delay due to anticoagulation), others are related to logistical factors (e.g., inadequate staffing). Identification and reduction of logistical delays via systemic interventions have the potential to significantly improve the value of care delivered.

The “weekend effect“ is a well-described phenomenon in which patients admitted on weekends have less favorable clinical outcomes and higher mortality rates than those patients admitted on weekdays, often attributed to decreased staffing during the weekends[1-5]. In terms of endoscopy, weekends provide less specialized nursing and anesthesia availability compared to a typical weekday[6-10]. Most studies involving factors leading to delays in inpatient colonoscopies have often focused on strategies in improving bowel preparation as that is an established cause of increased hospital LOS and cause of colonoscopy delays[11-13]. However, modifiable logistical factors, such as timing of consultation, that lead to delays in inpatient colonoscopies have not been extensively studied.

Our primary aim is to identify modifiable, logistical factors leading to inpatient colonoscopy delays and increased LOS. We hypothesized that initial consultation on the weekend would be the dominant significant logistical factor contributing to inpatient colonoscopy delays resulting in increased LOS.

MATERIALS AND METHODS

Setting

We performed a retrospective cohort study of all inpatient colonoscopies conducted at a single academic medical center (Chicago, IL, United States) over a 15-month period from March 2018 to May 2019. All endoscopic procedures were performed at a single, tertiary academic hospital. A waiver of informed consent was obtained from our center’s Institutional Review Board (No. STU00211125).

Study design

Patient and procedure specific data were extracted from our institutional Enterprise Data Warehouse. The data warehouse is a single, integrated database of clinical and research data from all patients receiving treatment through Northwestern University healthcare affiliates. Using detailed manual chart review, the most common factors leading to inpatient colonoscopy delays were identified. Colonoscopies on inpatient hepatology service were excluded from analysis.

Study outcomes

The primary outcome was time to colonoscopy, defined as the number of hospital days from initial GI consultation to completion of colonoscopy. The secondary outcome was hospital LOS.

Definitions

We defined an inpatient colonoscopy delay using day-specific thresholds to account for the structural delay from the lack of a normal endoscopy weekend schedule limiting non-emergent colonoscopies. Consult notes signed Sunday through Thursday were classified as delayed if the colonoscopy was performed more than 1 calendar day after consultation regardless of the time of consult. Consult notes signed on Friday were classified as delayed if the colonoscopy was performed more than 3 calendar days after consultation, and consult notes signed on Saturday were classified as delayed if the colonoscopy was performed more than 2 calendar days after consultation. These thresholds reflect Monday as the earliest structurally feasible procedure date for Friday and Saturday consults, given that non-urgent colonoscopies are not routinely performed on weekends at our institution. A weekend consultation was defined as a GI consult note signed on Saturday or Sunday per sensitivity analyses. Hospital LOS was calculated as the number of calendar days from admission until discharge.

We defined and broadly identified two sources of colonoscopy delays: (1) Logistical delays; and (2) Clinical delays. Clinical delays included inadequate bowel preparation and acceptable delays including a change in clinical recommendations, need for further medical optimization, planned extended bowel preparation, and antithrombotic therapy. A change in clinical recommendations was identified when the GI consulting team did not initially recommend a colonoscopy but later recommended and performed one. A delay due to inadequate bowel preparation was noted when the patient was not passing clear bowel movements on the initial anticipated morning of procedure. We defined medical optimization as a delay due to management of other medical comorbidities. Planned extended bowel preparation was defined as the GI consulting team recommending a ≥ 2-day bowel preparation at the time of initial consultation. Delays due to use of antithrombotic therapy (e.g., a need to hold antiplatelet therapy for a specified time) were also identified. Logistical delays were identified and defined as: A delay either due to scheduling (full weekday schedule or avoidance of weekend non-emergent cases) or delayed initiation of a clear liquid or low residue diet at a time of consultation.

Admissions were stratified by detailed chart review into those in which the only admission indication was gastrointestinal disease-related (“GI-primary”) vs not. We defined GI-primary admissions as those that had only GI bleed, anemia, or other GI conditions listed as acute problems in the admission note problem list. If multiple conditions (both GI and non-GI related) were present in the problem list, the first listed problem was considered the primary reason for admission. If a GI diagnosis was listed first, then it was considered a GI-primary admission. If a non-GI diagnosis was listed first, then it would be considered a GI-secondary admission. If only non-GI acute problems were noted in the problem list, it was not considered a GI-related admission.

Statistical analysis

Descriptive statistics for continuous variables were reported as means and standard deviations for age and as median, interquartile range, and range for LOS. Continuous variables were compared between groups using Student’s t-test and categorical variables were reported as percentages and analyzed with χ² testing. A pre-specified logistic regression model was fit to identify factors associated with colonoscopy delay, with covariates selected a priori based on clinical rationale and prior literature: (1) Age; (2) Sex; (3) Ethnicity; (4) Weekend consultation (Saturday or Sunday); (5) Admission indication; (6) GI bleed; (7) Anemia; and (8) Other GI diagnosis on admission. Results were reported as adjusted odds ratio (OR) with 95%CI. Pre-specified negative binomial regression models were fit to determine factors influencing LOS among all procedures and among delayed procedures only, and to determine factors influencing time from consult note to procedure among all procedures. Least square mean estimates and 95%CI limits for length of delay and LOS were estimated from the models. Sensitivity analyses were performed evaluating three definitions of weekend consultation (Friday/Saturday, Saturday/Sunday, and Friday/Saturday/Sunday) to assess the robustness of the primary findings and to inform the final variable definitions used in the primary analysis.

RESULTS

Over the study period, a total of 890 inpatient colonoscopies were performed. Repeat colonoscopies during the same hospital stay (n = 31), colonoscopies on inpatient hepatology service patients (n = 60), or colonoscopies missing a consult note or other key information (n = 28) were excluded. A total of 771 inpatient colonoscopies remained, of which 302 (39.2%) were delayed (Table 1). In the 302 patients with a colonoscopy delay, we identified one or more factors associated with each colonoscopy delay. Of these 302 patients, 65.6% had only clinical delays, 14.9% had only logistical delays, and 19.5% had both clinical and logistical delays.

Table 1 Factors driving delay of colonoscopy procedures, n (%).

Factors associated with inpatient colonoscopy delay (may be more than one factor per delay)	Delayed colonoscopy procedures (n = 302)
Clinical delays
Change in clinical recommendations	160 (53.0)
Inadequate bowel preparation	55 (18.2)
Pending medical optimization	48 (15.9)
Planned extended bowel preparation	27 (8.9)
Esophagogastroduodenoscopy prior to colonoscopy	20 (6.6)
Holding anticoagulation/antiplatelet therapy for a specified time	8 (2.6)
Pending INR/platelets optimization	9 (3.0)
Logistical delays
Weekend scheduling limitations	53 (17.5)
Weekday scheduling limitations and/or failure to initiate a clear liquid diet	66 (21.9)

INR: International normalised ratio.

The most common contributor of delay was a change in clinical recommendations (n = 160, 53.0%). In 17.5% (n = 53), colonoscopy was not immediately performed due to weekend scheduling limitations. In 21.9% (n = 66), colonoscopy was delayed due to a full weekday schedule and/or failure to initiate an appropriate diet. Inadequate bowel preparation (n = 55, 18.2%) was a less common clinical cause of delay (Table 1).

Risk factors for colonoscopy delay

Sensitivity analyses evaluating three definitions of weekend consultation (Friday/Saturday, Saturday/Sunday, Friday/Saturday/Sunday) revealed that Friday consults did not carry excess delay risk once day-specific delay thresholds were applied, whereas Saturday and Sunday consults retained a significant association. Weekend consultation was therefore defined as Saturday/Sunday for primary analysis.

Among both delayed (n = 302) and non-delayed (n = 469) colonoscopies, age (60.2 years vs 59.5, respectively), ethnicity (86.4% non-Hispanic vs 82.9%), and sex (48.7% female vs 46.1%) were similar across groups (Table 2). Our logistic regression analysis of the descriptive factors between the two groups highlighted that colonoscopies with consult notes signed on the weekend (Saturday or Sunday) were associated with increased odds of delay (OR = 1.66; 95%CI: 1.16-2.37). Additionally, compared to having a GI-primary admission indication, having an admission that was not GI-primary (OR = 3.78; 95%CI: 1.92-7.52) and having both non-GI and GI admission indications (OR = 1.69; 95%CI: 1.22-2.34) were predictive of delay. After accounting for these factors, none of the other factors were predictive of a delayed procedure.

Table 2 General description by delay status, n (%).

Factor	Delayed procedures (n = 302)	Non-delayed procedures (n = 469)	P value
Age, mean (SD)	60.2 (17.6)	59.5 (18.2)	0.586
Sex			0.524
Male	155 (51.3)	253 (53.9)
Female	147 (48.7)	216 (46.1)
Ethnicity			0.422
Not Hispanic or Latino	261 (86.4)	389 (82.9)
Hispanic or Latino	30 (9.9)	60 (12.8)
Declined	11 (3.6)	20 (4.3)
LOS, median calendar days (interquartile range) (range)	8 (5-14) (2, 134)	4 (3-8) (1, 169)	< 0.001
Day of the week consult note signed			0.001
Monday	57 (18.9)	65 (13.9)
Tuesday	55 (18.2)	77 (16.4)
Wednesday	43 (14.2)	75 (16.0)
Thursday	36 (11.9)	105 (22.4)
Friday	30 (9.9)	60 (12.8)
Saturday	36 (11.9)	46 (9.8)
Sunday	45 (14.9)	41 (8.7)
Admission indication			< 0.001
No GI	38 (12.6)	27 (5.8)
Only GI	99 (32.8)	234 (49.9)
Both GI and other	165 (54.6)	208 (44.3)
GI bleed	85 (28.1)	194 (41.4)	< 0.001
Anemia	114 (37.7)	158 (33.7)	0.283
Other GI indication	145 (48.0)	214 (45.6)	0.566
Primary/secondary indications			< 0.001
No GI indications	38 (12.6)	27 (5.8)
GI Primary	201 (66.6)	396 (84.4)
Non-GI primary and GI secondary	63 (20.9)	46 (9.8)

LOS: Length of stay; GI: Gastrointestinal.

We also evaluated factors influencing the overall time from consultation note to procedure for all procedures and found that a longer time to procedure was associated with consult notes signed on the weekend vs weekday, age 50-75, sex, and admission indication (Table 3). GI bleed was associated with shorter time to procedure, though this did not reach statistical significance (P = 0.085). Among a subset of patients whose admission indication was GI primary, procedures with consult notes signed on the weekend [OR = 1.74 (1.15, 2.62)] was associated with a delay to procedure. The time from note to colonoscopy was significantly less in patients with a GI bleed [1.7 days (0.1)] compared to those without [2.4 days (0.2)].

Table 3 Influential factors for time to procedure among all procedures.

Factor	Mean time to procedure, days (95%CI)	P value
Age
< 50	2.7 (2.2-3.1)	Ref
50-75	2.3 (1.9-2.7)	0.048
> 75	2.3 (1.9-2.7)	0.1
Sex
Male	2.2 (1.9-2.6)	Ref
Female	2.6 (2.2-3.0)	0.033
Ethnicity
Not Hispanic or Latino	2.7 (2.4-2.9)	Ref
Hispanic or Latino	2.6 (2.1-3.1)	0.79
Declined	2.0 (1.3-2.8)	0.104
Day of week
Weekday consultation (Monday-Friday)	2.1 (1.8-2.5)	Ref
Weekend consultation (Saturday-Sunday)	2.7 (2.3-3.2)	0.001
Admission indication
Only GI	1.7 (1.4-2.0)	Ref
No GI	3.3 (2.6-4.1)	< 0.001
Both GI and non-GI (GI primary)	2.1 (1.7-2.4)	0.038
Both GI and non-GI (GI secondary)	2.7 (2.2-3.3)	< 0.001
On admission
No GI bleed	2.6 (2.2-3.0)	Ref
GI bleed	2.2 (1.9-2.7)	0.085

Ref: Reference; GI: Gastrointestinal.

Risk factors for increasing LOS

On the multivariate estimates of LOS among all procedures, longer LOS was associated with procedure delay, admission indication, absence of GI bleed, presence of “other GI diagnosis” on admission, and increasing patient age (Table 4). Among the delayed procedures, LOS was associated with admission indication, delays of procedure due to medication optimization, change in treatment recommendation, optimization of international normalised ratio/platelets, and if a subsequent scope was to be performed (Table 5). Among patients whose admission indication was GI-primary, LOS was also significantly shorter in patients with a GI bleed [4.9 days (SE = 0.4)] compared to those without [6.8 days (SE = 0.6)] (P = 0.005).

Table 4 Factors influencing length of stay among all procedures.

Factor	Mean LOS, days (95%CI)	P value
Age
< 50	12.5 (10.6-14.7)	Ref
50-75	11.2 (9.6-13.0)	0.135
> 75	10.2 (8.5-12.2)	0.02
Sex
Male	11.6 (10.1-13.4)	Ref
Female	10.9 (9.3-12.7)	0.283
Ethnicity
Not Hispanic or Latino	11.5 (10.4-12.7)	Ref
Hispanic or Latino	11.2 (9.3-13.4)	0.762
Declined	11.1 (8.2-15.1)	0.833
Day of the week
Weekday consultation (Monday-Friday)	11.5 (10.1-13.2)	Ref
Weekend consultation (Saturday-Sunday)	11.0 (9.2-13.0)	0.477
Admission Indication
No GI	5.8 (5.0-6.7)	Ref
Only GI	21.1 (16.3-27.2)	< 0.001
Both GI and non-GI (GI primary)	8.1 (7.0-9.3)	< 0.001
Both GI and non-GI (GI secondary)	16.2 (13.4-19.6)	< 0.001
On admission
No GI bleed	12.4 (10.9-14.2)	Ref
GI bleed	10.2 (8.5-12.2)	0.01
No other GI diagnosis1	9.8 (8.5-11.2)	Ref
Other GI diagnosis1	13.0 (10.9-15.4)	< 0.001
Procedure status
Non-delayed	9.5 (8.1-11.0)	Ref
Delayed	13.4 (11.5-15.6)	< 0.001

¹Gastrointestinal diagnosis that is not anemia or gastrointestinal bleed.

Ref: Reference; LOS: Length of stay; GI: Gastrointestinal.

Table 5 Factors influencing length of stay among delayed procedures.

Factor	Mean LOS, days (95%Cl)	P value
Age
< 50	32.8 (18.4-58.5)	Ref
50-75	33.5 (19.4-58.2)	0.828
> 75	28.8 (16.6-49.9)	0.297
Sex
Male	31.1 (18.0-53.8)	Ref
Female	32.2 (18.4-56.2)	0.713
Ethnicity
Not Hispanic or Latino	32.0 (19.0-53.9)	Ref
Hispanic or Latino	40.3 (22.7-71.6)	0.111
Declined	24.5 (12.2-49.3)	0.269
Admission indication
No GI	57.7 (31.3-106.3)	Ref
Only GI	19.7 (11.4-34.2)	< 0.001
Both GI and non-GI (GI primary)	25.3 (14.6-43.8)	0.019
Both GI and non-GI (GI secondary)	34.7 (19.6-61.7)	< 0.001
On admission
No GI bleed	34.8 (20.5-59.1)	Ref
GI bleed	28.7 (16.1-51.4)	0.079
No other GI diagnosis1	28.5 (16.8-48.4)	Ref
Other GI diagnosis1	35.1 (19.6-62.8)	0.059
Planning extended bowel preparation	33.6 (18.1-62.4)	Ref
No delay	29.8 (17.8-49.7)	0.454
Holding anticoagulation/antiplatelets	38.6 (18.8-79.3)	Ref
No delay	25.9 (16.3-41.3)	0.141
Inadequate bowel preparation	32.7 (18.1-59.0)	Ref
No delay	30.7 (18.2-51.8)	0.609
Pending medical optimization delay	36.0 (19.8-65.5)	Ref
No delay	27.8 (16.6-46.5)	0.037
Change in clinical recommendations delay	43.3 (24.0-78.1)	Ref
No delay	23.1 (13.7-38.9)	< 0.001
EGD prior to colonoscopy delay	26.7 (14.4-49.6)	Ref
No delay	37.5 (22.0-63.8)	0.077
Pending INR/platelets optimization delay	46.6 (23.3-93.3)	Ref
No delay	21.5 (13.3-34.6)	0.001
Required subsequent colonoscopy	47.2 (24.8-89.9)	Ref
No subsequent colonoscopy	21.2 (12.5-36.0)	< 0.001
Weekend scheduling	32.8 (18.6-58.1)	Ref
No delay	30.5 (17.7-52.5)	0.519
Weekday scheduling/failure to initiate clear liquid diet	33.2 (18.2-60.6)	Ref
No delay	30.2 (18.2-50.2)	0.43

¹Gastrointestinal diagnosis that is not anemia or gastrointestinal bleed.

Ref: Reference; LOS: Length of stay; GI: Gastrointestinal; INR: International normalised ratio; EGD: Esophagogastroduodenoscopy.

DISCUSSION

Logistical factors that drive inpatient colonoscopy delays and their impact on hospital LOS have been minimally studied in current literature. In this single institution, retrospective cohort study, we found that logistical factors contributed to delay in almost half of the delayed procedures. These logistical factors included limitations due to a weekend schedule, a full weekday schedule, and/or failure to initiate a clear liquid diet upon consultation. Additionally, procedural delay was associated with longer LOS. In our subgroup analysis excluding procedures with non-GI admission indications, we again found that colonoscopies with weekend consultation notes were associated with a delay. These results raise the hypothesis that establishing a dedicated weekend endoscopy schedule may benefit the hospital system and patients by decreasing procedural delays, LOS, and off-set hospitalization costs.

While patient emergencies are not timed to mimic the ambulatory work week, hospital resources and staffing often mirror a typical weekday outpatient schedule[6-10]. These limitations can be due to budgeting as well as employee work hour satisfaction[8,14]. Bell and Redelmeier[6] found that patients with certain life-threatening medical conditions were more likely to die in the hospital if admitted on the weekend vs weekday. In another study, Bell and Redelmeier[7] analyzed the time to procedure based on admission day for six specific procedures, including esophagogastroduodenoscopy, and found that only 5% of urgent procedures were performed on the weekend and patients admitted on Friday and Saturday had the longest procedure wait times and longer total in-hospital stays. Furthermore, Cram et al[8] found that for certain diagnoses, patients admitted on weekends had slightly higher mortality, and this weekend effect was more prominent in major teaching hospitals.

Beyond clinical outcomes, lack of an endoscopy weekend schedule also results in delays in non-emergent procedures until the next available weekday. A prior study showed that patients are less likely to undergo endoscopy on the second day of admission when admitted on the weekend compared to weekday admissions and was associated with increased hospital LOS and hospital costs[9]. Conversely, our prior work found a significant decrease in hospital LOS and a trend towards decreased hospital costs when patients underwent a weekend endoscopic retrograde cholangiopancreatography instead of delaying the procedure until Monday[10].

While this weekend effect has been repeatedly seen throughout literature[6-10], the generalizability of these results across specialties[11] and hospital systems is difficult given different practice patterns and management guidelines for various conditions[14-18]. There are six studies looking at the weekend effect in GI endoscopic practices and outcomes, but the results are inconsistent[9,10,19-22]. Abougergi et al[19] conducted a GI-specific study on the impact of day of admission on mortality and other outcomes in upper GI hemorrhage. They found that patients with nonvariceal upper GI hemorrhage admitted on weekends compared to weekdays had comparable mortality rates and LOS but lower endoscopy rates and higher hospitalization charges[19]. Li et al[20] examined the weekend effect in lower GI bleeding and noted early colonoscopy was more common for weekday admissions, but this did not impact colonoscopy rate, mean days to colonoscopy, or LOS.

Our results add to the current limited body of literature in this area that GI consultations completed on the weekend compared to weekdays are more likely to have an inpatient colonoscopy delay which in turn, influences LOS. Colonoscopy delays have been associated with increased LOS in prior studies, with estimated cost increases ranging from $3300-$7200 per patient[23,24]. In our analysis, even after accounting for calendar artifact with a more conservative delay definition, a significant “weekend effect” persisted, suggesting that delays with Saturday and Sunday consultations reflect true resource and staffing limitations beyond what scheduling alone can explain. This could be attributable to decreased staffing on the weekend with more junior employees making it more difficult to operate with similar volume and safety as the weekdays[6,25]. Furthermore, employees have less work satisfaction when working on the weekend; however, identifying potential ways (including incentivization) to offset this dissatisfaction can be identified[6,26].

Admission indication also emerged as an important predictor of delay, with non-GI and mixed GI and non-GI admissions carrying higher odds of delay compared to GI-only admissions. This may reflect several compounding factors in non-GI admissions: (1) Lower prioritization of colonoscopy with competing clinical concerns; (2) Delays in initiating bowel preparation; and (3) Scheduling conflicts with other procedures or testing required for the primary indication. Collectively, these barriers suggest that standardized cross-team communication pathways such as automated preparation order sets triggered at the time of GI consultation or dedicated inpatient GI inpatient services could help reduce delays in this population[5]. Additionally, among patients with a GI-only admission indication, LOS was significantly shorter in those with a GI bleed compared to those without, and there was a non-significant trend toward shorter time to procedure in GI bleed patients across the full cohort. This is consistent with clinical prioritization of GI bleed colonoscopies given their greater urgency and suggests that non-GI bleed colonoscopies, while less immediately urgent, may still benefit from improved weekend resource allocation to reduce unnecessary delays and prolonged hospital stays.

There are important strengths and weakness of the study that require highlighting. Strengths include a large sample size in a large tertiary care hospital system and ability to identify the multiple drivers of delay through a detailed and systematic chart review. The limitations of our study include the possibility that those admitted on the weekends have additional unrecognized comorbidities compared to those admitted on the weekdays, which could confound the observed association between weekend consultation and delay. While our pre-specified multivariable model adjusted for several potential confounders including age, sex, ethnicity, and admission indication, residual confounding from unmeasured comorbidity burden cannot be fully excluded. We attempted to account for this confounder by doing a subgroup analysis for those with only GI admission indications and found similar results that consult notes signed on Saturday or Sunday were associated with procedural delay. Future studies incorporating validated comorbidity indices such as the Charlson Comorbidity Index may better account for this potential confounder. Furthermore, our dataset did not include a measure of clinical urgency, precluding stratification of delays by urgency of the case. Another limitation is that holidays and time of consult note were unaccounted for, which could also impact staffing and timely procedure preparation. Additionally, generalizability may be limited by differing practices in non-academic settings where staffing models, endoscopy scheduling, and case volumes will differ. Moreover, the data for this study were collected between March 2018 and May 2019, predating the coronavirus disease 2019 pandemic. The pandemic substantially altered inpatient endoscopy workflows, weekend staffing models, and value-based care incentives, which may limit the generalizability of these findings to current clinical practice. Finally, this study did not include a cost or outcome analysis to see if delay in procedure affected these factors, which could be explored in future studies.

CONCLUSION

Modifiable logistical factors including weekend scheduling issues are significant drivers of inpatient colonoscopy delay. Non-logistical, acceptable factors were also predominant, though are more difficult to address due to being inherently non-modifiable. Colonoscopies with Saturday and Sunday GI consultation notes were at increased odds of having a colonoscopy delay. Additionally, non-GI and mixed GI admission indications were associated with increased odds of delay, suggesting that cross-team communication regarding colonoscopy preparation and scheduling urgency represents an additional target for intervention. Furthermore, delays to colonoscopy were associated with a longer LOS. Based on these results, weekend resource allocation warrants further prospective evaluation, including cost-effectiveness analyses to determine whether the LOS reductions justify the costs of expanded endoscopy staffing with a weekend endoscopy schedule. Future prospective quality-improvement studies may also uncover other modifiable logistical factors or unaccounted confounders.