Bismuth Quadruple Therapy Versus Modified Bismuth Therapy for Helicobacter Pylori

Study Design: Open label randomized controlled trial (RCT). Period of study:From September 2023 to September 2025 Participants: Among patients attending Gastroenterology clinic in Tropical medicine and infectious diseases department-Tanta university;200 patients with a confirmed diagnosis of helicobacter pylori infection were enrolled and allocated randomly in 2 equal parallel treatment arms.

Sample Size Calculation:

The sample size was calculated using a free online clinical trial calculator (ClinCalc.com) based on effect sizes from previous studies. A recent study in KSA reported an eradication rate of 78.3% for bismuth-based quadruple therapy [1]. Conversely, other studies have reported eradication rates of 88-94% [2] and 91.5-97.3% [3] for bismuth-based triple therapy. At a 95% confidence interval (α-error = 0.05) and 80% statistical power (β-error = 0.2), the minimum required sample size was 146 patients, allocated equally (73 per arm) [4]. To account for an anticipated attrition rate of approximately 30% a total of 200 patients (100 per group) were recruited.

Randomization and Allocation:

To ensure unbiased group assignment and concealment of the allocation sequence, a computer-generated randomization scheme was implemented. Block randomization was performed using a block size of 4, with computer-generated random permutations within each block. To minimize the risk of predicting the allocation sequence, the block size was randomly varied using blocks of 4 and 6 and was not disclosed to the treating investigator. Each enrolled patient was assigned a unique numerical identifier. The complete list of patient identifiers was then sorted in ascending order according to the generated random values. Based on this sorted sequence, the first 100 patients were allocated to Group I (Bismuth add on triple therapy), while the remaining 100 patients were assigned to Group II (Bismuth quadruple therapy). To maintain allocation concealment, the randomization sequence was generated by an independent investigator who was not involved in patient enrollment or outcome assessment. Group assignments were placed in sequentially numbered, opaque, sealed envelopes, which were opened just before starting treatment and after the enrolling physician confirmed patient eligibility and obtained written his/her informed consent.

All patients in the study will be subjected to the following:

Full history taking. Complete clinical examination. Laboratory Investigations including: complete blood picture, liver function tests and renal function tests.

Abdominal ultrasound. Confirm ation of H.pylori infection with either: quantification of H. pylori antigen in stool by ELISA, r upper gastrointestinal endoscopic biopsy and histopathological examination.