Adequate bowel preparation is critical for successful colonoscopy, yet inadequate preparation remains a significant clinical challenge, occurring in 20-30% of procedures. In hospitalized patients undergoing therapeutic colonoscopy, suboptimal preparation leads to increased costs, prolonged hospital stay, and potential procedure cancellation or rescheduling. Current standard care involves resident ward rounds twice daily. This cluster-randomized crossover trial aims to evaluate whether increasing the frequency of structured resident ward rounds from 2 to 4 times per day can improve bowel preparation quality in hospitalized patients scheduled for therapeutic colonoscopy. The enhanced ward round intervention includes standardized checklist review, medication verification, dietary compliance confirmation, adverse event screening, and timely intervention when needed. Three hospital wards will be randomly assigned to different sequences of intervention and control periods using a crossover design with washout periods. The primary outcome is adequate bowel preparation quality assessed by Boston Bowel Preparation Scale (BBPS ≥6 with each segment ≥2), evaluated by blinded endoscopists. Secondary outcomes include procedure quality metrics (cecal intubation rate, examination duration), safety endpoints (electrolyte disturbances, aspiration events), health economics measures (length of stay, total costs), and healthcare worker burden (nursing workload, night-time call frequency). Subgroup analyses will examine intervention effects across age groups, cognitive function levels, prior colonoscopy experience, and comorbidity burden to identify populations most likely to benefit from enhanced monitoring. This pragmatic trial addresses a clinically relevant question using a real-world implementation strategy designed to minimize workflow disruption. Results will inform evidence-based policies regarding optimal ward round frequency for colonoscopy preparation in hospital settings.
Background and Rationale Adequate bowel preparation is essential for high-quality colonoscopy. The Boston Bowel Preparation Scale (BBPS) is a validated tool for assessing preparation quality, with scores ≥6 (and each segment ≥2) considered adequate. Studies report inadequate preparation rates of 20-30% in routine practice, leading to missed lesions, prolonged procedures, and increased costs. Hospitalized patients face unique challenges for bowel preparation including comorbidities, cognitive impairment, medication complexity, and communication barriers. While outpatient preparation often relies on written instructions and telephone reminders, inpatients theoretically benefit from direct medical supervision. However, the optimal frequency and structure of ward rounds during bowel preparation remain undefined. Current practice at our institution includes twice-daily resident ward rounds (morning and afternoon). We hypothesize that increasing ward round frequency to four times daily (adding midday and evening rounds) with a standardized intervention package will improve preparation quality by: 1. Enhanced medication compliance monitoring 2. Real-time dietary adherence verification 3. Early detection and management of adverse events 4. Improved patient education and anxiety reduction 5. Timely adjustment of preparation regimens Study Design This is a single-center, cluster-randomized, crossover trial with three hospital wards serving as clusters. Each ward will alternate between intervention and control periods in a balanced sequence with washout periods to minimize carryover effects. Design Features: * Cluster Unit: Hospital ward (to avoid contamination within same care team) * Crossover Design: Each ward serves as its own control across time periods * Washout Periods: 1-week washout between intervention periods * Blinded Outcome Assessment: Endoscopists remain blinded to patient allocation Timeline Structure: * Phase 0 (Weeks 0-1): Protocol training and system testing * Phase 1 (Weeks 2-5): First intervention period (4 weeks) * Washout 1 (Week 6): Transition period * Phase 2 (Weeks 7-10): Second intervention period (4 weeks) * Washout 2 (Week 11): Transition period * Phase 3 (Weeks 12-15): Third intervention period (4 weeks) * Weeks 16-17: Data cleaning and database lock Randomization: An independent biostatistician will generate a randomization sequence using Williams design for 3×3 crossover. Ward assignments will be concealed in sealed envelopes and revealed to ward supervisors only at the start of each period. Interventions Control Group (Standard Care): * Ward rounds: 2 times/day (morning 7:30-9:00, afternoon 15:00-17:00) * Standard clinical assessment during rounds * Verbal confirmation of preparation instructions Intervention Group (Enhanced Ward Rounds): * Ward rounds: 4 times/day (morning 7:30-9:00, midday 12:00-13:00, afternoon 15:00-17:00, evening 21:00-22:00) * Duration: ≥10 minutes per patient per round * Standardized intervention package at each round: 1. Medication Verification: Confirm PEG dose, timing, completion rate; assess tolerance (nausea, bloating) 2. Dietary Compliance Check: Review food/fluid intake in past 4 hours; correct any deviations (e.g., family-provided meals, solid foods) 3. Adverse Event Screening: Assess for electrolyte imbalance symptoms (weakness, palpitations, muscle cramps), aspiration risk (vomiting with cough), dehydration signs 4. Clinical Decision Support: Prescribe antiemetics for severe nausea; adjust PEG rate for bloating; order electrolyte testing if indicated 5. Patient Education Assessment: (First and pre-procedure evening rounds only) Three-question quiz on preparation instructions; re-educate if \<2/3 correct Adherence Monitoring: Electronic time-stamped check-in via mobile app at each ward round, with mandatory completion of standardized checklist (cannot submit if \<10 minutes elapsed). Standardized Elements (Both Groups): To isolate the effect of ward round frequency, all other aspects remain identical: * Preparation Regimen: Split-dose PEG (2L at D-1 18:00, 1L at D-day 6:00) * Diet Protocol: Low-residue diet at D-2, clear liquids only at D-1 * Patient Education: Written handbook + 8-minute video within 24h of admission * Rescue Protocol: Additional 500ml PEG or enema on examination morning if residual stool reported Outcome Measures Primary Outcome: * Adequate bowel preparation rate: Proportion of patients achieving BBPS total score ≥6 AND each segment score ≥2 * Assessment: During colonoscopy by blinded endoscopist * Timeframe: At time of colonoscopy procedure Key Secondary Outcomes: 1. BBPS total score (continuous, 0-9 scale) 2. Cecal intubation rate and time (minutes) 3. Total examination duration (minutes) 4. Adenoma detection rate (ADR) 5. Preparation-related adverse events (electrolyte abnormalities, aspiration, vomiting requiring medication) 6. Procedure rescheduling/repeat preparation rate 7. Length of hospital stay (days) 8. Total hospitalization costs (RMB) 9. Patient satisfaction score (5-point Likert scale) 10. Night-time nurse call frequency (21:00-7:00, normalized per patient) 11. Nursing workload assessment score Subgroup Analyses (Pre-specified): * Age: \<60 / 60-74 / ≥75 years * Cognitive function: Normal / mild impairment / moderate-severe impairment * Prior colonoscopy: Yes / No * Charlson Comorbidity Index: 0-2 / 3-4 / ≥5 Statistical Analysis Plan The primary analysis will use a generalized linear mixed model (GLMM) with logit link for the binary primary outcome, including fixed effects for treatment, period, and sequence, and random effects for ward. An intention-to-treat approach will be employed. Sample size of 268 evaluable patients (134 per group) provides 80% power to detect an absolute increase from 75% to 90% in adequate preparation rate, assuming ICC=0.03 and two-sided α=0.05. Sensitivity analyses will include per-protocol population (excluding participants with \<75% adherence to assigned ward round frequency), complete case analysis, and varying ICC assumptions. Subgroup effects will be assessed through treatment-by-subgroup interaction terms. Safety Monitoring The independent DSMB will conduct one interim analysis at 50% enrollment. Pre-specified stopping rules include: * Significant increase in serious adverse events (SAEs) in intervention group (RR\>2.0, p\<0.01) * Overwhelming efficacy (preparation rate difference \>20%, p\<0.001) All SAEs will be reported to the IRB within 24 hours. Quality Control * BBPS rater training: All endoscopists complete standardized training with 20 reference videos; inter-rater reliability (Kappa) \>0.75 required * Calibration meetings every 4 weeks to review borderline cases * Electronic data capture (REDCap) with real-time validation rules * Weekly data monitoring by research coordinator with 10% source verification
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
300
Increase resident physician ward round frequency from 2 to 4 times per day (adding midday 12:00-13:00 and evening 21:00-22:00 rounds). Each ward round includes standardized checklist-based assessment covering medication adherence, dietary compliance, adverse events, and patient understanding. Duration ≥10 minutes per patient. Electronic documentation with time stamps ensures adherence monitoring.
Standard care with resident physician ward rounds twice daily at morning (7:30-9:00) and afternoon (15:00-17:00). Routine clinical assessment and verbal confirmation of preparation protocol. Represents current practice standard.
The First Hospital of Lanzhou University
Lanzhou, Gansu, China
Adequate Bowel Preparation Rate
Proportion of patients achieving adequate bowel preparation defined as Boston Bowel Preparation Scale (BBPS) total score ≥6 points AND each colonic segment score ≥2 points. BBPS is a validated 0-9 point scale (3 segments × 0-3 points each) assessing preparation quality during colonoscopy. Endoscopist records BBPS score for each segment (right colon, transverse colon, left colon) after cleansing maneuvers during colonoscopy. Adequate preparation requires both: (1) total score ≥6 and (2) no segment with score \<2. Endoscopists remain blinded to patient group assignment.
Time frame: Assessed during colonoscopy procedure (Day 0, examination day)
Boston Bowel Preparation Scale (BBPS) Total Score
BBPS total score as continuous variable (range 0-9), with higher scores indicating better preparation quality
Time frame: Assessed during colonoscopy procedure (Day 0)
Cecal Intubation Rate
Proportion of procedures achieving successful cecal intubation, confirmed by visualization of ileocecal valve and appendiceal orifice
Time frame: Assessed during colonoscopy procedure (Day 0)
Cecal Intubation Time
Time in minutes from scope insertion at anal verge to cecal intubation
Time frame: Assessed during colonoscopy procedure (Day 0)
Total Examination Duration
Total procedure time in minutes from scope insertion to scope withdrawal
Time frame: Assessed during colonoscopy procedure (Day 0)
Adenoma Detection Rate (ADR)
Proportion of patients in whom at least one adenoma is detected during colonoscopy, confirmed by pathology
Time frame: Assessed at time of pathology report (within 2 weeks post-procedure)
Preparation-Related Adverse Events
Composite outcome including: (1) Electrolyte abnormalities (potassium \<3.5 or \>5.5 mmol/L, sodium \<135 or \>145 mmol/L); (2) Aspiration events (vomiting with cough and pulmonary signs); (3) Severe nausea/vomiting requiring medication; (4) Dehydration requiring IV fluids
Time frame: From initiation of bowel preparation (Day -1) through colonoscopy completion (Day 0), approximately 24-36 hours
Procedure Rescheduling Rate
Proportion of patients requiring colonoscopy rescheduling or repeat bowel preparation due to inadequate initial preparation
Time frame: Within 7 days of originally scheduled procedure
Length of Hospital Stay
Total number of days from hospital admission to discharge
Time frame: From admission until discharge, expected average of 5-10 days
Total Hospitalization Costs
Total direct medical costs in Chinese Yuan (CNY) including room charges, medications, procedures, and laboratory tests, extracted from hospital information system
Time frame: From admission until discharge, expected average of 5-10 days
Patient Satisfaction Score
Patient-reported satisfaction with bowel preparation guidance assessed on 5-point Likert scale (1=very dissatisfied to 5=very satisfied)
Time frame: Within 24 hours after colonoscopy completion (Day 0)
Patient Preparation Tolerance
Patient-reported tolerance of preparation process on 5-point Likert scale (1=not difficult at all to 5=unbearable)
Time frame: Within 24 hours after colonoscopy completion (Day 0)
Night-time Nurse Call Frequency
Number of patient-initiated nurse calls during night hours (21:00-7:00), normalized per patient, extracted from nurse call system records
Time frame: Night before colonoscopy (Day -1 evening to Day 0 morning), approximately 10 hours
Nursing Workload Score
Nurse-reported workload assessment for each patient's bowel preparation period, assessed on 5-point Likert scale (1=same as routine patients to 5=significantly increased burden)
Time frame: Assessed at end of preparation period, within 24 hours after colonoscopy (Day 0)
Patient Knowledge Score
Patient understanding of preparation instructions assessed by 3-item questionnaire (timing of second PEG dose, permissible fluids, medication speed). Score range 0-3 with higher scores indicating better understanding.
Time frame: Evening before colonoscopy (Day -1, approximately 18:00-22:00)
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