Emami 2014.

Methods	Aim of study: this study evaluated the impact of adding NAC to quadruple regimens ofH pylori eradication. Study design: randomised controlled study, open‐label. Study grouping: parallel group. Unit of allocation: by individuals. Country: Iran. Start date: September 2010. End date: July 2012. Duration of participation: 8 weeks. Ethical approval: this study was approved by the local ethics committee.
Participants	Total number randomised: 180. Method of recruitment: consecutive participants between 17 and 80 years of age complaining of dyspeptic symptoms who referred to the Gastroenterology Clinics of Al‐Zahra hospital, Noor, Poursina Hakim Research Center and Ardakan hospital for endoscopy by a gastroenterologist between September 2010 and July 2012 recruited with full consent if H pylori tests were positive (confirmed by histology, rapid urease test, or stool antigen test). Informed consent obtained: full consent. Baseline imbalances: no difference observed between groups. Withdrawals and exclusions: 59 participants were lost for follow‐up and only one drop out in the ABCO group with significant side effects, leading to therapy cessation before completion of treatment. Subgroups measured: not reported. Subgroups reported: not reported. Mean age: group A (42.3 ± 13.9 years) and group B (47.1 ± 13.9 years). Gender (M/F): group A (27/33) and group B (30/31). Race/ethnicity: not available in report. Severity of condition: non‐ulcer disease (44%), duodenal ulcer (15%), gastric ulcer (1%). Comorbidities: not available in report. Diagnostic criteria:H pylori tests positive (confirmed by histology, rapid urease test, or stool antigen test). Setting: Gastroenterology Clinics of Al‐Zahra hospital, Noor, Poursina Hakim Research Center and Ardakan hospital. Inclusion criteria: all participants between 17 and 80 years of age complaining of dyspeptic symptoms with H pylori tests positive (confirmed by histology, rapid urease test, or stool antigen test). Exclusion criteria: participants having previously received eradication of H pylori treatment, presence of underlying disease such as cirrhosis, renal failure, severe cardiac disease, malignancy outside the gastrointestinal (GI) tract, the need for simultaneous use of non steroid anti inflammatory drugs (NSAIDs), the need for concomitant use of steroids or other immunosuppressive drugs, recent gastrointestinal bleeding, pregnancy, or lactating mothers.
Interventions	Number randomised in each group: group A (n = 60), group B (n = 61). Dose Group A (ABCO): amoxicillin (from Farabi co. Iran) 500 mg 4 times daily, bismuth citrate (from Arya co. Iran) 120 mg 4 times daily, omeprazole (from Abidi co. Iran) 20 mg twice daily, and clarithromycin (from Tolidarouco. Iran) 500 mg twice daily as standard therapy. Group B (ABCON): amoxicillin (from Farabi co. Iran) 500 mg 4 times daily, bismuth citrate (from Arya co. Iran) 120 mg 4 times daily, omeprazole (from Abidi co. Iran) 20 mg twice daily, and clarithromycin (from Tolidarou co. Iran) 500 mg twice daily as standard therapy with effervescent fluimucil (NAC from Swiss Zambon co. Swiss) 600 mg tablets twice daily. Duration of treatment period: 14 days. Timing: as described above. Delivery: as described above. Providers: not reported. Cointerventions: none. Economic information: not reported. Resource requirements: not reported. Integrity of delivery: not reported. Compliance: a total of 107 (87.2%) participants took > 85% of the prescribed treatment, which was considered good compliance.
Outcomes	Primary outcomes: eradication rates, defined as the number of participants with negative H pylori stool antigen test (generic assay‐Dahlewitz‐Germany) after treatment. Secondary outcomes: side effects, defined as complaints determined by a specific questionnaire completed by the participants during the treatment period. Time points measured and reported: four to six weeks after treatment. Person measuring/reporting: not reported. Unit of measurement: individual. Scales: none. Imputation of missing data: the eradication rates, their 95% confidence intervals (CIs) at ITT analysis (all included participants), and per protocol (PP) analysis (all participants who took > 85% of prescribed treatment) were calculated. Assumed risk estimates: not reported. Power: not reported.
Notes	Publication status: full text. Funding source: Isfahan University of Medical Sciences. Conflict of interest: authors have no competing interests. Contact with authors: we contacted the authors on 26 January 2017 but received no answer.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients were randomly assigned in one of two H pylori eradication regimens..." Comment: insufficient information to allow judgement.
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information to allow judgement.
Blinding of participants and personnel (performance bias) Eradication (frequency)	Low risk	Quote: "In an open‐label, randomized controlled trial...H pylori stool antigen test (generic assay‐Dahlewitz‐Germany) was performed to evaluate the effectiveness of the eradication" Comment: it was an open label study, but eradication rate was assessed byH pylori stool antigen test (generic assay‐Dahlewitz‐Germany) (objective test).
Blinding of participants and personnel (performance bias) Gastrintestinal adverse events	High risk	Quote: "In an open‐label, randomized controlled trial..." Comment: this outcome could be influenced by the lack of blinding.
Blinding of participants and personnel (performance bias) Allergic adverse events	High risk	Quote: "In an open‐label, randomized controlled trial..." Comment: this outcome could be influenced by the lack of blinding.
Blinding of participants and personnel (performance bias) Toxic adverse events	High risk	Quote: "In an open‐label, randomized controlled trial..." Comment: this outcome could be influenced by the lack of blinding.
Blinding of outcome assessment (detection bias) Eradication (frequency)	Low risk	Quote: "In an open‐label, randomized controlled trial...H pylori stool antigen test (generic assay‐Dahlewitz‐Germany) was performed to evaluate the effectiveness of the eradication" Comment: it was an open label study, but eradication rate was assessed by H pylori stool antigen test (generic assay‐Dahlewitz‐Germany) (objective test).
Blinding of outcome assessment (detection bias) Gastrintestinal adverse events	High risk	Quote: "In an open‐label, randomized controlled trial..." Comment: this outcome could be influenced by the lack of blinding.
Blinding of outcome assessment (detection bias) Allergic adverse events	High risk	Quote: "In an open‐label, randomized controlled trial..." Comment: this outcome could be influenced by the lack of blinding.
Blinding of outcome assessment (detection bias) Toxic adverse events	High risk	Quote: "In an open‐label, randomized controlled trial..." Comment: this outcome could be influenced by the lack of blinding.
Incomplete outcome data (attrition bias) Eradication (frequency)	High risk	Comment: there was 32.7% losses. No reasons were provided, nor the methods used for data imputation. This fact could substantially influence the results.
Incomplete outcome data (attrition bias) Gastrintestinal adverse events	High risk	Comment: there was 32.7% losses. No reasons were provided, nor the methods used for data imputation. This fact could substantially influence the results.
Incomplete outcome data (attrition bias) Allergic adverse events	High risk	Comment: there was 32.7% losses. No reasons were provided, nor the methods used for data imputation. This fact could substantially influence the results.
Incomplete outcome data (attrition bias) Toxic adverse events	High risk	Comment: there was 32.7% of losses. No reasons were provided, nor the methods used for data imputation. This fact could substantially influence the results.
Selective reporting (reporting bias)	Low risk	All proposed outcomes were properly presented.
Other bias	Low risk	This study seems to be free of other sources of bias.