[Randomized and nonrandomized controlled clinical trials in a German surgical journal]

A bibliometric analysis of the citation classics of acute appendicitis

INTRODUCTION

Acute appendicitis is one of the most commonly encountered emergency surgical conditions. An understanding of the most highly cited research works in this field is key to good evidence based clinical practice.

AIMS

To perform a bibliometric analysis on the 100 most frequently cited articles in the field of acute appendicitis.

METHODS

The database of the Institute for Scientific Information (ISI) Web of Science Expanded citation index was searched to identify the 100 most frequently cited articles in the field of acute appendicitis. The web of science expanded citation index tracks article citations made since 1946.

RESULTS

The top 100 most frequently cited articles were selected for analysis in this series. The most frequently cited article was cited 649 times and the least cited three article 93 times. The average number of citations per article was 167.74. The top 100 cited articles originated from 17 countries. Over half of the papers originated from the USA. Fifty-one of the papers concentrated on diagnostics of acute appendicitis. Thirty-six papers looked at the treatment of acute appendicitis with 30 of these dealing with the surgical management of the disease. There were 6 studies at level 1a, 20 studies at level 1b and 43,5,17 and 9 studies at levels 2, 3, 4 and 5 respectively.

CONCLUSIONS

Bibliometric analysis of the citation classics in a given field can provide interesting insights into the relationship between the quality of research outputs and clinical practice. The study of acute appendicitis remains an active field of research with a growing body of higher quality evidence underpinning our clinical practice.

Surgical evaluation and knowledge transfer--methods of clinical research in surgery

PURPOSE

This article aims to outline the framework of surgical evaluation and knowledge transfer. Therefore, special design issues affecting surgical clinical research will be discussed. Moreover, principles and challenges of knowledge transfer from research into practice will be addressed.

BACKGROUND

The ultimate goal of academic surgery is to improve surgical and perioperative care in order to achieve the best outcomes for patients. Randomized controlled trials and reviews with and without meta-analyses are fundamental requirements for evidence-based decision making.

DISCUSSION

Despite calls for more rigorous research methods in surgery, the frequency of high-quality randomized controlled trials and systematic reviews is low. Specific methodological and design issues have to be implemented for valid evaluation of surgical procedures. Thus, general catchwords of clinical epidemiology such as timing, randomization, registration, and reporting standards demand special appraisal. Moreover, blinding methods, placebo controls, learning curves, standardized outcome assessment, and generalizability are critical design issues in surgical trials. Moreover, systematic reviews and meta-analyses are desirable for answering clinical issues or defining new research questions.

CONCLUSION

For a rigorous evaluation of surgical procedures, a basic understanding of research methodology is urgently needed, and to improve methodological expertise, collaboration between surgeons and methodologists is encouraged.

Limits to clinical trials in surgical areas

Randomized clinical trials are considered to be the gold standard of evidence-based medicine nowadays. However, it is important that we point out some limitations of randomized clinical trials relating to surgical interventions. There are limitations that affect the external and internal validity of many surgical study designs. Some limitations can be bypassed, but can make it more difficult for the study to be carried out. Other limitations cannot be bypassed. When it is intended to extrapolate the result of a randomized clinical trial, the premise is that the performed or to be performed intervention will be similar wherever applied and/or for every doctor using it. However, no matter how standardized the technique may be, the results are not similar for all surgeons, which implies a significant limitation to surgical randomized clinical trials concerning external validity. When considering the various limitations presented for performing surgical trials capable of generating scientific evidence within the patterns currently proposed in the evidence level classifications of medical publications, it is necessary to rethink whether those scientific evidence levels are similarly applicable to surgical works and to nonsurgical trials. We currently live in a time of supposed ''inferiority'' of surgical scientific works under the optics of the current quality criteria for a ''suitable'' clinical trial.

[Hand searching for controlled clinical trials in German surgical journals. A contribution to evidence-based surgery]

BACKGROUND

The identification of all available and relevant study reports is mandatory for a comprehensive assessment of randomised (RCTs) and controlled clinical trials (CCTs) in systematic reviews. Incomplete compilation of health care journals in electronic databases and incorrect indexing of the studies impair the result of a systematic literature search. An additional search in medical journals that are not listed in electronic databases can obtain higher search precision.

METHODS

In the hand searching project of the Cochrane Collaboration, in Germany 14 surgical journals were searched manually for RCTs and CCTs. The identified study reports were compared with Medline records, and the publication frequency was analysed. The study reports were published in the Cochrane Library and are henceforth available for inclusion in systematic reviews.

RESULTS

Four hundred (77%) of the 519 published volumes in the 14 surgical journals were searched for RCTs and CCTs. Of the 1152 controlled trials (670 RCTs and 482 CCTs) identified, 674 (58%) were not included in Medline.

CONCLUSIONS

The gap between the number of hand search results and the number of Medline indexed RCTs and CCTs is also reflected in other special medical fields. To ensure completeness of the literature compilation, the hand searching project should be continued.

[Randomized controlled and controlled clinical trials in German-language ophthalmological journals]

BACKGROUND

The medical database MEDLINE contains only a part of all published randomized controlled (RCTs) and controlled clinical (CCTs) trials. The validity of a systematic review depends on the complete consideration of all studies pertaining to a clinical question. Therefore, a manual systematic search in medical journals is mandatory.

METHODS

The last 30 years of the three peer-reviewed German-language ophthalmological journals Der Ophthalmologe, Klinische Monatsblätter für Augenheilkunde, and Spektrum der Augenheilkunde were retrospectively searched for controlled trials. All identified RCTs and CCTs were classified according to their ophthalmological subspecialty. The quality of the studies was evaluated using the CONSORT Statement. Moreover, a comparison was made of how many of the studies identified by hand searching are registered in MEDLINE and correctly classified as RCTs/CCTs.

RESULTS

In total 984 RCTs and CCTs were identified; 62% of the trials were from the subspecialty anterior eye segment, 14% belonged to the subspecialty posterior eye segment, and 18% belonged to glaucoma. A sample size calculation was reported in less than 2% of the full-text publications and 34% reported a blinded study design. A randomization process was described in 23% of the RCTs. Most controlled trials were published in the 1990s in all three journals. From 1998 onward, there was a decrease in the number of published controlled trials in the reviewed German literature. About 63% of the studies registered in MEDLINE are correctly classified.

CONCLUSION

In the specialty of ophthalmology there are many important studies which provide basic information for compilation of systematic reviews and clinical guidelines. However, many of the identified clinical trials in German-language journals show deficiencies in the study quality. Only a part of the identified controlled trials are correctly classified in MEDLINE. Therefore, a retrospective registration is essential to complete the electronic database in ophthalmology.

A concept for trial institutions focussing on randomised controlled trials in surgery

Background

Although considered the reference standard for generating valid scientific evidence of a treatment's benefits and harms, the number of Randomised Controlled Trials (RCT) comparing surgical techniques remains low. Much effort has been made in order to overcome methodological issues and improve quality of RCTs in surgery. To the present there has been, however, only little emphasis on development and maintenance of institutions for implementation of adequately designed and conducted surgical RCTs.

Mehods/Design

Description of the developments in surgical RCT infrastructure in Germany between 2001 and 2006. Cross sectional evaluation of completed and ongoing surgical RCTs within the German Surgical Society and the Clinical Study Centre, Department of Surgery, University of Heidelberg.

Results

Foundation of a national Clinical Trial Centre (CTC) for the organisation of multi-centre RCTs in the surgical setting (Study Center of the German Surgical Society, SDGC). Establishment of a network of CTCs with affiliated Clinical Sites (CSs) to enhance patient recruitment and shorten the duration of RCTs. Since its foundation four surgical RCTs with a total sample size of 1650 patients (1006 of these randomised) have been supervised by the SDGC with 35 CSs involved in patient recruitment. Five further CTCs were set up in 2006. Together with their affiliated CSs a network has been organised providing improved conditions for the conduction of surgical RCTs.

Conclusion

Improvement of infrastructure substantially facilitates integration of RCTs into routine surgical practice. A network of collaborating CTCs and CSs can provide an adequate infrastructure for the conduction of multi-centre RCTs.

[Systematic reviews and meta-analyses in surgery]

The enormous number of medical publications available online and in print media makes it difficult for surgeons to keep abreast of new scientific developments. In addition to information overload and lack of time, studies of questionable quality and expertise when performing systematic literature searches jeopardize proper surgical decision making. The concept of systematic reviews (SR) and meta-analyses (MA) is based on a critically appraised synthesis of individual trials addressing comparable medical problems. This qualitative evaluation and quantitative aggregation of research findings offer valid decision making tools for the clinician, scientist, and health care authorities. Systematic reviews employ comprehensive methods to control for potential bias when synthesizing individual trials. Thus the clinical question and methodological aspects should be defined a priori in a protocol. In the following step the relevant literature must be identified through systematic searches in databases. After critical assessment of the methodological quality and heterogeneity of individual studies, the results can be presented qualitatively. They also can be quantitatively summarized in MA if appropriate. Compared to single trials, properly conducted SR and MA facilitate more precise estimation of the treatment effect of surgical interventions. Hence they represent an ideal basis for future research endeavors. In conclusion, SR and MA implemented in clinical guidelines, evidence-based consumer information, or health technology assessment, enable the necessary bridging between research and clinical practice.