OBJECTIVE: The natural history of asymptomatic (silent) gallstones has been inadequately studied. Existing information derives from studies based on oral cholecystography or relatively small sample sizes. We planned a retrospective cohort study in subjects with gallstones to determine conversion rates from asymptomatic to symptomatic.
METHODS: We extracted data from computerised databases of one government hospital and two private clinics in Malaysia. Files were scrutinised to ensure that criteria for asymptomatic gallstones were fulfilled. Patients were called on telephone, further questioned to confirm that the gallstones at detection were truly asymptomatic, and asked about symptoms that were consistent with previously defined criteria for biliary colic. Appropriate ethical clearances were taken.
RESULTS: 213 (112 males) patients fulfilled the criteria for asymptomatic gallstones and could be contacted. 23 (10.8%) developed pain after an average follow up interval of 4.02 years (range 0.1-11 years). Conversion rates from asymptomatic to symptomatic gallstones were high in the first two years of follow up, averaging 4.03±0.965 per year. Over time the conversion rates slowed, and by year 10 the annual conversion rate averaged only 1.38±0.29. Conversion rates were much higher for females compared to males (F:M hazard ratio 3.23, SE 1.54, p>z 0.014). The lifetime risks for conversion approached 6.15% for males, and 22.1% for females.
CONCLUSION: In conclusion, asymptomatic gallstones are much more likely to convert to symptomatic in females than in males. Males in whom asymptomatic stones are discovered should be advised conservative treatment. Surgery may be preferable to conservative management if the subject is a young female.
m radiology records of Hospital
Study site: Computerised database, Hospital Selayang, Selangor; private clinics, Kuala Lumpur, Malaysia
Background Citations of papers are positively influenced by the journal's impact factor (IF). For non-open access (non-OA) journals, this influence may be due to the fact that high-IF journals are more often purchased by libraries, and are therefore more often available to researchers, than low-IF journals. This positive influence has not, however, been shown specifically for papers published in open access (OA) journals, which are universally accessible, and do not need library purchase. It is therefore important to ascertain if the IF influences citations in OA journals too. Methods 203 randomized controlled trials (102 OA and 101 non-OA) published in January 2011 were included in the study. Five-year citations for papers published in OA journals were compared to those for non-OA journals. Source papers were derived from PubMed. Citations were retrieved from Web of Science, Scopus, and Google Scholar databases. The Thompson-Reuter's IF was used. Results OA journals were found to have significantly more citations overall compared to non-OA journals (median 15.5 vs 12, p=0.039). The IF did not correlate with citations for OA journals (Spearman's rho =0.187, p=0.60). The increase in the citations with increasing IF was minimal for OA journals (beta coefficient = 3.346, 95% CI -0.464, 7.156, p=0.084). In contrast, the IF did show moderate correlation with citations for articles published in non-OA journals (Spearman's rho=0.514, p<0.001). The increase in the number of citations was also significant (beta coefficient = 4.347, 95% CI 2.42, 6.274, p<0.001). Conclusion It is better to publish in an OA journal for more citations. It may not be worth paying high publishing fees for higher IF journals, because there is minimal gain in terms of increased number of citations. On the other hand, if one wishes to publish in a non-OA journal, it is better to choose one with a high IF.