Zala 1994.
| Methods |
Aim of study: to test the hypothesis whether better eradication results could be achieved by addition of NAC to omeprazole/amoxicillin. Study design: randomised controlled study, open‐label. Study grouping: parallel group. Unit of allocation: by individuals. Country: Switzerland. Start date: not available in report. End date: not available in report. Duration of participation: 8 weeks. Ethical approval: not reported. |
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| Participants |
Total number randomised: 34. Method of recruitment: not reported. Informed consent obtained: not reported. Baseline imbalances: not reported. Withdrawals and exclusions: none. Subgroups measured: smokers/non‐smokers. Subgroups reported: smokers/ non‐smokers. Mean age: group A (46 years), group B (39 years). Gender (M/F): group A (12/5), group B (15/2). Race/ethnicity: group A (1 Swiss, 10 from Eastern Europe/Mediterranean, 1 Iranian), group B (3 Swiss, 11 from Eastern Europe/Mediterranean, 3 from other countries). Severity of condition: duodenal ulcer. Comorbidities: not reported. Diagnostic criteria:H pylori infection confirmed by histology (3 biopsy specimens from gastric antrum and 2 from gastric body) and at least positive urease test or culture. Setting: outpatients. Inclusion criteria: outpatients with endoscopically documented recurrent duodenal ulcer. Exclusion criteria: alcoholism, previous gastric surgery, or intake of antibiotics, omeprazole, bismuth salts, corticosteroids or NSAIDs 4 weeks before study entry. |
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| Interventions |
Number randomised in each group: group A (n = 17), group B (N = 17). Dose:
Duration of treatment period: 10 days. Timing: as described above. Delivery: not reported. Providers: not reported. Co‐interventions: not reported. Economic information: not reported. Resource requirements: not reported. Integrity of delivery: not reported. Compliance: not reported. |
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| Outcomes |
Primary outcome: eradication rates, defined as the number of participants with rapid urease test negative, culture negative and absence of bacteria in histologic examination. Secondary outcome: adverse events (undefined). Time points measured and reported: 4 weeks after treatment. Person measuring/reporting: not reported. Unit of measurement: ‐ Scales: ‐ Imputation of missing data: not reported. Assumed risk estimates: not reported. Power: not reported. |
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| Notes |
Publication status: full text. Funding source: not reported. Conflict of interest: authors declared no conflicts. Contact with authors: we contacted the authors on 26 January 2017 but received no reply |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "Ineinerprospektiven,randomisierten offenen studie wurden duodenalulkuspatient ennachdem H.‐pylori‐Nachweis einer von zwei Therapie gruppenzugeteilt" (translation: "In a prospective, randomized open study, duodenal ulcer patients were randomized to H pylori detection of one of two therapy groups.") 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: "Ineinerprospektiven,randomisierten offenen studie wurden duodenalulkuspatient ennachdem H.‐pylori‐Nachweis einer von zwei Therapie gruppenzugeteilt" (translation: "In a prospective, randomized open study, duodenal ulcer patients were randomized to H pylori detection of one of two therapy groups.") Comment: it was an open label study, but eradication rate was assessed by rapid urease test (objective test). |
| Blinding of participants and personnel (performance bias) Gastrintestinal adverse events | High risk | Quote: "In a prospective, randomized open study.." Comment: this was an open label study. This outcome could be influenced by the lack of blinding. |
| Blinding of participants and personnel (performance bias) Allergic adverse events | High risk | Quote: "In a prospective, randomized open study.." Comment: this was an open label study. This outcome could be influenced by the lack of blinding. |
| Blinding of participants and personnel (performance bias) Toxic adverse events | High risk | Quote: "In a prospective, randomized open study.." Comment: this was an open label study. This outcome could be influenced by the lack of blinding. |
| Blinding of outcome assessment (detection bias) Eradication (frequency) | Low risk | Quote: "Ineinerprospektiven,randomisierten offenen studie wurden duodenalulkuspatient ennachdem H.‐pylori‐Nachweis einer von zwei Therapie gruppenzugeteilt" (translation: "In a prospective, randomized open study, duodenal ulcer patients were randomized to H pylori detection of one of two therapy groups.") Comment: it was an open label study, but eradication rate was assessed by rapid urease test (objective test). |
| Blinding of outcome assessment (detection bias) Gastrintestinal adverse events | High risk | Quote: "In a prospective, randomized open study.." Comment: this was an open label study. This outcome could be influenced by the lack of blinding. |
| Blinding of outcome assessment (detection bias) Allergic adverse events | High risk | Quote: "In a prospective, randomized open study.." Comment: this was an open label study. This outcome could be influenced by the lack of blinding. |
| Blinding of outcome assessment (detection bias) Toxic adverse events | High risk | Quote: "In a prospective, randomized open study.." Comment: this was an open label study. This outcome could be influenced by the lack of blinding. |
| Incomplete outcome data (attrition bias) Eradication (frequency) | Low risk | There were no losses. |
| Incomplete outcome data (attrition bias) Gastrintestinal adverse events | Low risk | There were no losses. |
| Incomplete outcome data (attrition bias) Allergic adverse events | Low risk | There were no losses. |
| Incomplete outcome data (attrition bias) Toxic adverse events | Low risk | There were no losses. |
| 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. |
GI: gastrointestinal H pylori: Helicobacter pylori ITT: intention‐to‐treat mg: milligram n: number NAC: N‐acetylcysteine NSAIDs: non‐steroidal anti‐inflammatory drugs