Chiou YE. et al., 2022: A Comparative Study of Stone Re-Treatment after Lithotripsy.
Chiou YE, Chung CH, Chien WC, Tsay PK, Kan HC, Weng WH.
Department of Nursing, College of Medicine, Fu Jen Catholic University, New Taipei City 242, Taiwan.
Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei City 114, Taiwan.
School of Public Health, National Defense Medical Center, Taipei City 114, Taiwan.
Taiwanese Injury Prevention and Safety Promotion Association, Taipei City 114, Taiwan.
Department of Public Health and Center of Biostatistics, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.
Division of Urology, Department of Surgery, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
Department of Chemical Engineering and Biotechnology and Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei City 106, Taiwan.
The high recurrence rate has always been a problem associated with urolithiasis. This study aimed to explore the effectiveness of single interventions, combined therapies, and surgical and nonsurgical interventions. Herein, three lithotripsy procedures-extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), and ureteroscopic lithotripsy (URSL)-were assessed and a retrospective cohort was selected in order to further analyze the association with several risk factors. Firstly, a population-based cohort from the Taiwan National Health Insurance Research Database (NHIRD) from 1997 to 2010 was selected. In this study, 350 lithotripsy patients who underwent re-treatment were followed up for at least six years to compare re-treatment rates, with 1400 patients without any lithotripsy treatment being used as the comparison cohort. A Cox proportional hazards regression model was applied. Our results indicate that the risk of repeat urolithiasis treatment was 1.71-fold higher in patients that received lithotripsy when compared to patients that were not treated with lithotripsy (hazard ratio (HR) 1.71; 95% confidence interval (CI) = 1.427-2.048; p < 0.001). Furthermore, a high percentage of repeated treatment was observed in the ESWL group (HR 1.60; 95% CI = 1.292-1.978; p < 0.001). Similarly, the PCNL group was also independently associated with a high chance of repeated treatment (HR 2.32; 95% CI = 1.616-3.329; p < 0.001). Furthermore, age, season, level of care, and Charlson comorbidities index (CCI) should always be taken into consideration as effect factors that are highly correlated with repeated treatment rates.
Life (Basel). 2022 Dec 16;12(12):2130. doi: 10.3390/life12122130. PMID: 36556495
At first glance, the paper seems to offer a good insight into the stone business from the recurrence aspect. The material and method section tells a slightly different story than the abstract. There are several major biases in this study.
The author never actually looked at patients but at the data from the Taiwan National Health Insurance Research Database. All targeted patients were diagnosed with urolithiasis between 1 January 2005 and 31 December 2005. However, the included codes were ICD-9CM codes 592 (calculus of the kidney and ureter), 594 (calculus of the lower urinary tract) and 788.0 (renal colic). Lithotripsy included ESWL, PCNL, and URSL. After a matched control based on sex, age, and level of care they were left with 350 individuals who had active stone treatment and 1400 individuals who only had observation. The follow-up was to Dec. 2010. With a few drop outs the numbers came down to 204 of 341 (59,8%) patients actively re-treated in the previous lithotripsy cohort vs. 433 of 1375 (31,5%) actively treated in the primary conservative treatment group. This is the essential message.
The problem of the paper is the case selection, the matching, and the code selection. In principle, stone patients treated conservatively are very different from those who are actively treated. They differ in stone size, configuration, and position and probably analysis. Matching could not include any of these unknown factors as they are not part of the database. In addition, selection of ICD-9CM codes 592 and 788.0 (lower tract stones and renal colic resp.) included stones not treated by any of the lithotripsy techniques mentioned. They should not have been included in a comparative study. In German hospital statistics those two patients groups represented apr. 12% (15.500 of 127.000) of all stone patients in 2005. In the data presented, it is not shown how many of these cases were included in the conservative group.
The authors seem to have forgotten the hypothesis they formulated in the introduction: “We hypothesize that the effect of lithotripsy on the re-treatment of urolithiasis is based on an exposure-response relationship: a process by which the prevalence of the intervention increases as the size of the stone increase.” The paper includes no data on stone size.
In addition I was surprised to read that a paper we had published in 1993 (1) was referenced as having confirmed the accuracy and validity of the diagnoses in the Taiwan’s National Health Insurance Research Database (NHIRD) which was launched two years later in 1995 (2). Reading the present paper I remembered two publications we had previously reviewed which had used the same databank like the present authors (3,4).
In these two publications, the identical authors came to completely opposing conclusions on the same topic using the same databank without informing the reader about the contradicting aspect of their work. Not good!
This time I tried to find out more about the Taiwan National Health Insurance Research database (NHIRD) and found a term I had not yet met in the medical scientific community: (2). “Although a health care study might not always be driven by hypothesis, it is undeniable that the advances in computer techniques and the relatively lower cost of database maintenance have led to a considerable amount of “fishing expedition“ studies, which might be of disservice to health care big data research. For example, Hampson et al indicated that some researchers may misuse NHIRD to “produce” papers en masse by applying templates, without due consideration of the essence of scientific research. Such misconduct could damage the credibility of both the database and the research based on database.”(2).
For those who are interested in database fishing expeditions I recommend reading three other publication (5-7) on the use of the Taiwan National Health Insurance Research database (NHIRD). They offer many aspects of a blockbuster.
Those who want to know where the fishes from these expeditions are sold may in addition read an article (8) about the Multidisciplinary Digital Publishing Institute (MDP), which is the publisher of the present article. The latter article is currently under pressure (9).
“Oh! Oh! Oh! it's a lovely war.”
1 Köhrmann, K.U.; Rassweiler, J.; Alken, P. The recurrence rate of stones following ESWL. World J. Urol. 1993, 11, 26–30.
2 Hsieh CY, Su CC, Shao SC, Sung SF, Lin SJ, Kao Yang YH, Lai EC. Taiwan's National Health Insurance Research Database: past and future. Clin Epidemiol. 2019 May 3;11:349-358. doi: 10.2147/CLEP.S196293. PMID: 31118821; PMCID: PMC6509937.
3 Lu YM, Chien TM, Chou YH, Wu WJ, Huang CN. Is Extracorporeal Shock Wave Lithotripsy. Really Safe in Long-Term Follow-Up? A Nationwide Retrospective 6-Year Age-Matched Non-Randomized Study. Urol Int. 2017;98(4):397-402
4 Yen-Man Lu, Tsu-Ming Chien, Yii-Her Chou, Chun-Nung Huang,
Shock wave lithotripsy for renal stones is not associated with development of hypertension in Chinese/Taiwanese population, Urological Science, 2016; 27 (2) Supplement 1: S10, ISSN 1879-5226.
5 Lin CW, Chen WK, Hung DZ, Chen YW, Lin CL, Sung FC, Kao CH. Association between ischemic stroke and carbon monoxide poisoning: A population-based retrospective cohort analysis. Eur J Intern Med. 2016 Apr;29:65-70. doi: 10.1016/j.ejim.2015.11.025. Epub 2015 Dec 17. PMID: 26703428.
6 Hampson NB, Weaver LK. Carbon monoxide poisoning and risk for ischemic stroke. Eur J Intern Med. 2016 Jun;31:e7. doi: 10.1016/j.ejim.2016.01.006. Epub 2016 Jan 19. PMID: 26809864.
7 Wu YT, Lee HY. National Health Insurance database in Taiwan: A resource or obstacle for health research? Eur J Intern Med. 2016 Jun;31:e9-e10. doi: 10.1016/j.ejim.2016.03.022. Epub 2016 Apr 11. PMID: 27079475.
8 M Ángeles Oviedo-García, Journal citation reports and the definition of a predatory journal: The case of the Multidisciplinary Digital Publishing Institute (MDPI), Research Evaluation, Volume 30, Issue 3, July 2021, Pages 405–419,
9 Expression of concern: Journal citation reports and the definition of a predatory journal: The case of the Multidisciplinary Digital Publishing Institute (MDPI) M Ángeles Oviedo-García Research Evaluation, Volume 30, Issue 3, July 2021, Page 420, https://doi.org/10.1093/reseval/rvab030