The role of clinical trials in the development of novel surgical techniques

Assessing the Validity and Cover Rate of the National Swedish Hernia Register

Aim

To assess the validity and cover rate of the Swedish hernia register.

Material and Methods

Since the start of the Swedish Hernia register an annual review of randomly selected hospitals has been carried out, and since 2013 in a more standardized form to allow a systematic data collection and evaluation. 10% of all clinics were randomly selected each year in a specific region of Sweden, ensuring a systematic validation of all regions from north to south. Data from 2013 to 2018 were analyzed regarding data quality and from 2014 to 2018 regarding cover rate. All operations registered at the validated clinics were compared with the Swedish Hernia Register to assess cover rate. Fifty operations were randomly selected at each clinic and data in the Swedish Hernia register were compared with the medical records to evaluate data quality.

Results

Fifty-five clinics was evaluated and a total of 73,764 variables were compared with the medical records. Cover rate between 2014 and 2018 was 97%. The proportion of correct variables was 98% between 2013 and 2018. Most frequent errors were ASA score, date at which the patient was put on the waiting list and postoperative complications.

Conclusion

This unique validation of a national hernia register shows a high cover rate and good quality of data. Efforts to maintain and improve national registers are of great importance. Research with data from the Swedish hernia register should be evaluated on the basis of the results presented in this study.

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.