LA Classification Research Articles

IBC-Oxford University2023_BJSOral_24Comparison of postoperative GERD after LSG with omentopexy versus LSG without omentopexy, incidence of peri-operative GERD LSG in East Asia.

Abstract Background Gastroesophageal Reflux Disease (GERD) is known as the most common long-term complication after laparoscopic sleeve gastrectomy (LSG). The pathophysiology is assumed that the sleeved stomach after LSG is prone to be herniated through the hiatus with high intra- abdominal pressure in obese patients. The omentopexy is thought to make the remnant stomach fixed in abdominal cavity to decrease GERD symptom. Objectives This study aims to compare postoperative GERD after LSG with omentopexy versus LSG without omentopexy as well as to report incidence of peri-operative GERD LSG in East Asia with obesity. Methods This was a single-center retrospective comparative study. Patients with severe obesity (BMI > 35 or > 30 with second metabolic disease) who underwent LSG between January 2019 and June 2021 in Seoul National University Bundang Hospital were enrolled. Patient data were collected preoperatively and at postoperative 1 year. At each time point, body weight, laboratory tests and esophagogastroduodenoscopy were assessed. The patients were asked if anti-reflux medication including proton-pump inhibitor was taken and responded to GERD questionnaire. The validated Korean version of GERD-Q questionnaire was utilized. Laparoscopic sleeve gastrectomy was performed in the usual manner, with or without omentopexy. Omentopexy was defined as the suturing the stapled stomach to the omentum which must include upper part of the sleeve. Electric medical and surgical records were evaluated by the surgeons who were specialized in gastrointestinal surgery. The primary outcome was GERD incidence evaluated by three criteria: LA classification on esophagogastroduod enoscopy, GERD-Q score and anti-reflux medication history. Results During the study period, 106 and 62 patients were enrolled in the LSG with omentopexy group (LSGO) and LSG without omentopexy group (LSGWO) respectively. The baseline demographics did not significantly differ from each group. The mean age of LSGO group was 37.8 years (standardized deviation [SD] 11.0 years] and that of LSGWO group was 38.4 years [SD 10.9 years] (p=0.959). The LSGO and LSGWO groups were comprised of 34.0% and 35.5% men (p=0.868). There were no significant differences in surgical outcomes and postoperative complications between two groups. On GERD, there was no significant difference in LA classification and anti-reflux medication proportion between two groups after postoperative 1 year. However, LSGO group showed significantly less GERD-Q score (mean, SD; 6.57, 1.56) than LSGWO group (mean, SD; 7.91, 3.0) (p=0.02), which represented less subjective GERD symptoms in LSGO group. Conclusion People with obesity who underwent laparoscopic sleeve gastrectomy combined with omentopexy showed less GERD symptoms 1 year after operation than those who without omentopexy.

Tumeurs de la thyroïde : nouveautés de la classification OMS 2022

Tumeurs de la thyroïde : nouveautés de la classification OMS 2022

Apports et limites de la FISH dans le diagnostic des tumeurs du système nerveux central selon la classification de l’OMS de 2021 : retour d’expérience du service de neuropathologie de l’hôpital Sainte-Anne

The fifth edition of the World Health Organization (WHO) Classification of Tumors of the Central Nervous System has identified many new tumor types and has established, for the first time, essential and desirable diagnostic criteria for each of them. Among these, genetic alterations play an important role associated with morphology. For the first time, epigenetic data can also constitute essential and/or desirable criteria. These genetic abnormalities can be fusions, deletions or gains/amplifications and can thus be detected by fluorescence in situ hybridization techniques. The purpose of this article is to present the advantages and limitations of this technique in reference to its specific use within neuro-oncopathology in light of the 2021 WHO classification.

135. A COMPARISON OF THE INOUE ASSESSMENT METHODS AND THE HILL GRADING OF THE GASTROESOPHAGEAL JUNCTION IN DIAGNOSING REFLUX SYMPTOM SEVERITY, ESOPHAGITIS, AND GERD AMONG PATIENTS WHO UNDERWENT UPPER GI ENDOSCOPY IN A TERTIARY HEALTHCARE FACILITY

Abstract Gastroesophageal reflux disease (GERD) results from failure of the anti-reflux barriers in the gastroesophageal junction. Inoue proposed cardiac opening (CO), sliding hernia (SH), and scope holding time (SHT%) to assess this junction. To compare these Inoue methods and the Hill grade in diagnosis of severe GERD symptoms, moderate–severe esophagitis and GERD. Patients scheduled for gastroscopy off proton pump inhibitors were included. Symptoms were assessed using the GERDQ score. Esophagitis was determined using the modified LA Classification. The gastroesophageal junction was described using the Inoue methods and the Hill grade. The Inoue methods individually and as a composite score were compared to Hill grade. We were unable to reach our target sample size of 91. Only 69 patients were included. In severe GERD symptom diagnosis (GERDQ ≥11), Inoue score (composed of CO and SH with 1 point each) had good performance (AUC 0.87, 95%CI 0.70–1.04). In moderate–severe esophagitis diagnosis (LA grades B-D), SH (AUC 0.73, 95%CI 0.58–0.88) and Inoue score (AUC 0.79, 95%CI 0.64–0.94) had fair performance. In GERD (either GERDQ ≥8 or esophagitis) diagnosis, Inoue score (AUC 0.88, 95%CI 0.80–0.97) and CO (AUC 0.76, 95%CI 0.63–0.89) had fair-good performance. The rest had poor or failed values. Inoue score had fair-good performance in diagnosing severe GERD symptoms, moderate–severe esophagitis and GERD. Sliding hernia had fair performance in diagnosing moderate–severe esophagitis. CO had fair performance in diagnosing GERD. SHT% and Hill grade were poor/failed for all outcomes.

Republication : Aliments ultra-transformés : le système NOVA est-il robuste ?

La classification NOVA répartit les aliments en quatre groupes (de 1, peu transformé à 4, le plus transformé). Sa fiabilité et sa reproductibilité ont été très peu explorées alors qu’elle est très utilisée. Nous avons étudié la cohérence entre utilisateurs (environ 170 professionnels) de l’affectation de 120 aliments du commerce et 111 aliments génériques dans les groupes NOVA. La cohérence des affectations (κ de Fleiss) était de 0,32 (aliments du commerce) et 0,34 (aliments génériques). Des clusters d’aliments présentant des distributions d’affectations similaires ont été définis par classification hiérarchique. Parmi les aliments du commerce, un cluster réunissait 90 aliments très largement affectés à NOVA4 (91 % des affectations) et, parmi les aliments génériques, trois clusters contenaient des aliments principalement affectés à NOVA 1 (79 %), NOVA2 (75 %) et NOVA4 (70 %), respectivement. Les affectations étaient particulièrement hétérogènes pour 30 aliments du commerce et 28 aliments génériques (25 % du total dans les deux cas). Les critères actuels de la classification NOVA ne permettent pas d’affecter de manière non ambiguë un aliment à un groupe. Ce système doit être amélioré, en raison de son utilisation en recherche et dans les politiques publiques. In the NOVA classification system, descriptive criteria are used to assign foods to one of four groups based on processing-related criteria. Although NOVA is widely used, its robustness and functionality remain largely unexplored. We determined whether this system leads to consistent food assignments by users. French food and nutrition specialists completed an online survey in which they assigned foods to NOVA groups. The survey comprised two lists: one with 120 marketed food products with ingredient information and one with 111 generic food items without ingredient information. We quantified assignment consistency among evaluators using Fleiss’ κ (range: 0–1, where 1 = 100% agreement). Fleiss’ κ was 0.32 and 0.34 for the marketed foods ( n = 159 evaluators) and generic foods ( n = 177 evaluators), respectively. The consistency of the assignments, as assessed by Fleiss’ κ, was 0.32 (commercial foods) and 0.34 (generic foods). Clusters of foods with similar assignment distributions were defined by hierarchical ascending classification. Among the 120 commercial foods, one cluster contained 90 foods that were predominantly assigned to NOVA4 (91% of the assignments) and, among the 111 generic foods, three clusters contained foods that were predominantly assigned to NOVA 1 (79% of the assignments), NOVA2 (75%) and NOVA4 (70%), respectively. Assignments were particularly heterogeneous for 30 commercial and 28 generic foods (25% of the total in both cases). Although assignments were more consistent for some foods than others, overall consistency among evaluators was low, even when ingredient information was available. These results suggest current NOVA criteria do not allow for robust and functional food assignments.

788 VARIABLE GEOGRAPHICAL DIFFERENCES OF AMBULATORY ESOPHAGEAL REFLUX MONITORING IN MEXICO

Abstract Ambulatory esophageal reflux monitoring (AEpH) is useful in evaluating persistent or refractory esophageal symptoms despite adequate pharmacologic and/or surgical therapy. There is limited information whether there are geographical or regional differences in the diagnostic outcome of this test. Aim Characterize the diagnostic outcome of AEpH in a diverse population of Mexico. Analyze whether there is regional geographical diagnostic variability. Methods Data was collected from four major referral centers representing diverse geographical areas of Mexico: Mexico City-Central (two centers, years 2016-2020), Veracruz-South (years 2015-2020) and Monterrey-North (years 2013-2020). Consecutive patients undergoing AEpH with persistent GERD symptoms despite PPI therapy and negative upper endoscopy (no erosive disease >C or D LA classification) were entered into a data base and analyzed. Patients were classified as: NERD (acid exposure time (AET > 6.0%); hypersensitive esophagus (normal AET and positive symptom index (SI) or positive symptom association probability [SAP]); functional heartburn (NL AET, neg SI/SAP). Statistics: ANOVA, Chi-square and descriptive methods were used to compare variables among groups. Results 969 cases met inclusion criteria: 311 (32.1%) Central, 430 (44.3%) South, and 228 (23.5%) North. The results are summarized in the table. There were more women 618(63.8%) than men 351(36.2%); p < 0.001 with a mean age 47.7 ± 14.3. Patients were older in Central-Mexico 49.3 ± 13.6 years vs South 47.5 ± 15 and North 46.1 ± 13.6; p = 0.033. Functional heartburn was the most common diagnosis overall and more prevalent in Central-Mexico 171(55%) vs North 97(42.5%) and South 160(37.2%); p < 0.001. NERD was more predominant in the South 171(39.8%) vs North 72(31.6%) and Central-Mexico 98(31.5%); p = 0.029. Hypersensitive esophagus was more frequent in the North 59(25.9%) vs South 99(23%), and Central 42(13.5%); p < 0.001. Conclusion This is the first large data base study to evaluate the outcome of ambulatory esophageal reflux pH testing in Mexico. Our findings indicate a geographical variability of GERD phenotypes and suggest that further investigations are warranted to determine the causes of this distribution.

Relationship Between GERD-Q Score with Esophagitis Findings in Endoscopy

Background: Gastro-esophageal Reflux Disease (GERD) is a disease that is commonly found in daily practice and affecting the patients’ quality of life negatively. GERD-Q is a tool in the form of validated questionnaire that is quite useful and easy to use in daily practice to diagnose GERD by symptoms and signs especially in primary care that do not have endoscopy facilities. This study was built to assess the correlation between GERD-Q score and esophagitis finding in upper gastrointestinal endoscopy in Pekanbaru. Method: This was a prospective cross-sectional study with sample groups of GERD-Q score ≥8 (high GERD-Q score) and GERD-Q score 8 (low GERD-Q score) which underwent upper gastrointestinal endoscopy to assess reflux esophagitis. GERD-Q score data were obtained by direct interview.Results: This study was participated by 65 subjects with reflux esophagitis and 51 non-esophagitis patients that had undergone upper gastrointestinal endoscopy procedure. The 65 subjects with reflux esophagitis were divided into groups based on severity (LA Classification), Grade A 29 subjects (45%), Grade B 23 subjects (35%), Grade C 11 subjects (16%), and Grade D 2 subjects (3%). The result of this study showed that there was a statistically significant correlation between GERD-Q score category with esophagitis findings from upper gastrointestinal endoscopy (p 0.05, PR = 2.6)Conclusion: There is a statistically significant correlation between GERD-Q score and esophagitis findings from endoscopy but no relevance in esophagitis severity.

Sa1233 EFFECT OF VONOPRAZAN ON PPI-RESISTANT REFLUX ESOPHAGITIS

In 2015, Vonoprazan (VPZ), which exerts more potent and sustained acid-inhibitory effects than PPIs, became commercially available. In this study, we examined the efficacy of 4-week VPZ initial therapy at 20 mg for PPI-resistant RE, as well as that of 8-week and 52-week VPZ maintenance therapy at 10 mg in patients achieving healing. The subjects were 26 patients with PPI-resistant RE in whom esophageal mucosal breaks persisted despite administration of standard-dose PPIs for 8 weeks or more (13 males, 13 females, mean age: 70.0 years, LA classification grade A: 3 patients, B: 7, C: 13, and D: 3). All patients were negative for H. pylori infection (after eradication: 3 patients). In 25 patients, hiatal hernia measuring 2 cm or larger was detected (3 cm or larger: 19 patients). After confirming endoscopic healing by 4-week 20mg VPZ initial therapy, maintenance therapy with 10 mg VPZ was performed. Endoscopy was performed at 8 and 52 weeks after the initiation of maintenance therapy to evaluate whether there was any recurrence of RE. The study was discontinued for patients with recurrent RE at 8 weeks. Symptoms were assessed using the frequency scale for the symptoms of gastroesophageal reflux disease (F-scale) on days 1-7, 14, and 28 after the initiation of 20mg VPZ and at 8 and 52 weeks following the maintenance therapy with 10mg VPZ. Gastrin level was measured before breakfast at 8 and 52 weeks following the therapy. In 22 (84.6%) of the 26 patients, esophageal mucosal breaks were healed, whereas esophageal mucosal breaks of grade C persisted in 3 patients and grade A in one patient. The median F-score was significantly lower on days 1-7, 14, and 28 after the initiation of VPZ than before its administration. After 10mg VPZ maintenance therapy for 8 weeks, recurrence of RE was found in 4 patients (18.2%). These patients had LA grade C of RE. Eighteen patients (81.8%) maintained remission at 8 weeks continued on the maintenance therapy with 10mg VPZ until 52 weeks. While 2 patient had recurrent RE (grade B and C) at 52 weeks, the remaining 16 patients (88.9%) maintained remission. Overall remission maintenance rate of 10 mg VPZ at 52 weeks for PPI-resistant RE was 16 out of 22 patients (72.7%). There were no significant differences in the F-scale score at 8 and 52 weeks, nor the average gastrin score at 8 and 52 weeks (1055 and 832, respectively). 4-week initial therapy with 20mg VPZ was effective for patients with PPI-resistant RE. After an initial treatment for 4-week with 20mg VPZ, 52-week maintenance therapy with 10-mg vonoprazan is also effective for them especially in whom endoscopic healing was maintained by 8-week maintenance therapy with 10-mg VPZ. The efficacy of 20 mg VPZ initial therapy and 10 mg VPZ maintenance therapy for PPI-resistant RE patients were confirmed.

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 2

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 2

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 4

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 4

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 8

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 8

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : Cas no 3

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : Cas no 3

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 6

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 6

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 1

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : cas no 1

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : Cas no 5

Nouveautés et nouvelles pratiques en hématopathologie à l’ère de la classification OMS 2016 : Cas no 5

PS01.053: GASTRO-ESOPHAGEAL REFLUX TEST DECIDING SURGICAL INDICATION AND RESULTS OF LAPAROSCOPIC NISSEN FUNDOPLICATION FOR GERD PATIENTS

Abstract Background The indication of laparoscopic anti-reflux surgery for GERD patients is difficult to be judged fairly. We have established ‘Reflux Test‘ as the tool for the decision in the surgical indication for GERD patients. Methods Reflux Test At the standing position a patient swallows 300 ml barium solution. After total solution goes into stomach, a patient lies down at the flat position. Then a patient changes the position to left lateral decubitus position, flat position, right lateral decubitus position and flat position again every 10 seconds in the order. During this procedure, gastro-esophageal reflux was evaluated and assigned to severe, moderate and slight category. If the reflux was observed slightly up to cervical esophagus, the case was assigned to moderate category. If the reflux was observed intensely up to cervical esophagus, the position was returned to head high position for the safety and the case was assigned to severe category. The anti-reflux surgery was considered in the moderate and severe categories. Results We have performed laparoscopic Nissen procedure in 90 cases. The mean operation time of recent 20 cases was 90 min. The outcome was assessed by Reflux Test performed on 4–5 postoperative day, and the results showed no reflux in every cases. Median follow-up period of this study was 48 months (0–99 months). In 11 cases (12.6%) PPI was restarted before 6 months after the anti-reflux surgery. In 23 cases (25.6%) PPI was restarted after the anti-reflux surgery during the whole follow-up period of this study. The BMI of the patients had no relationship to the needed PPI restart. To evaluate the degree of esophagitis objectively before and after the anti-reflux surgery we designed ‘the esophagitis score’. In this scoring method, a number from 0–5 was assigned according to the degree of esophagitis along with the LA classification. The results of the study have shown that the reflux esophagitis was improved obviously after the anti-reflux surgery even in the PPI restarted group (P < 0.001). Conclusion Reflux Test is feasible because of its convenience and visual effects for the patients. The results of the laparoscopic Nissen fundoplication were good and satisfied by the patients mostly. Disclosure All authors have declared no conflicts of interest.

PS01.049: ENDOSTIM™ NON-RESPONDERS: AN ANALYSIS

Abstract Background Electronic stimulation oft the lower esophageal sphincter (LES) is a new promising anti-reflux procedure that is established in Germany since 2014. Basically two leads are inserted laparoscopicaly into the LES and connected to an implantable pulse generator (IPG) which is placed in a subcutaneous pocket. This stimulation is supposed to build up the muscular anti-reflux barrier. It is limited to patients with a small hiatal hernia < 3 cm and reflux esophagitis LA Classification Type A-C. Although long-term results up to 4 years with a good postoperative reflux control and an increased quality of life have been published, no data about Endostim™ non-responders, difficult postoperative situations and procedure failure has been reported yet. Methods Between 12/2015 and 11/2017 12 patients underwent laparoscopy for an Endostim™ implantation. All patients had an upper endoscopy, a barium swallow, high-resolution esophageal impedance manomentry (HRIM), 24-hour multi-channel impedance and pH monitoring (MII-pH) prior to the procedure and after 6 months. The quality of life was assessed with the GERD health related quality of life (GERD-HRQL) questionnaire preoperatively and during further follow-up. Results 6 of 12 patients (50%), 2 female 4 male, reported new GERD symptoms after an initial postoperative symptom relief. 1 patient had a prolonged period (15 months) of reprogramming until complete symptom control was achieved. 1 patient had a recurrent 3 cm hiatal hernia after 3 months, so that only a partial responds was reported. In 2 patients reprogramming could not reach a proper responds. Two patients showed a complete technical failure due to a broken lead close to the IPG. Conclusion Reasons for Endostim™ failure can be heterogeneous. Because it is a young and new procedure non-responders should be investigated closely so that there can be a critical discussion about indications, contraindications and negative predictive factors. Disclosure All authors have declared no conflicts of interest.

Nomenclatural Status of the Palaeobotanical “Artificial Taxa” Established in Brongniart’S 1822 “Classification” Paper

Brongniart’s 1822 paper “Sur la classification et la distribution des végétaux fossils” was one of the most important early contributions to palaeobotany, especially in its treatment of how to name and classify plant fossils. Twenty four genera / sections were named in this work. Seven of these names have been supressed for nomenclatural or taxonomic reasons (Exogenites, Clatharia, Sagenaria, Filicites, Phyllites, Poacites, Carpolithes), and four are difficult to use because of problems with typification and / or diagnosis of the taxa (Endogenites, Culmites, Fucoides, Antholithes). However, many of the remaining names are still in widespread use, albeit not always correctly, notably Calamites, Sigillaria, Stigmaria, Sphenopteris, Neuropteris, Pecopteris, Odontopteris, Sphenophyllum, Glossopteris, Asterophyllites, albeit with altered orthographies or conserved with different types

(25) Proposal to add Richard’s report in Bull. Sci. Soc. Philom. Paris 1822: 25—28. Feb 1822 of Brongniart’s later (May—Sep 1822) publication “Sur la classification ... des végétaux fossils” to the list of suppressed works for new generic names in the Code Appendices

TAXONVolume 67, Issue 3 p. 653-654 Proposals to Suppress WorksFree Access (25) Proposal to add Richard’s report in Bull. Sci. Soc. Philom. Paris 1822: 25—28. Feb 1822 of Brongniart’s later (May—Sep 1822) publication “Sur la classification ... des végétaux fossils” to the list of suppressed works for new generic names in the Code Appendices John McNeill, John McNeillSearch for more papers by this authorChristopher J. Cleal, Corresponding Author Christopher J. Cleal [email protected] Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, U.K.Search for more papers by this authorBarry A. Thomas, Barry A. Thomas Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, U.K. Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, SY231NL Aberystwyth, U.K.Search for more papers by this author John McNeill, John McNeillSearch for more papers by this authorChristopher J. Cleal, Corresponding Author Christopher J. Cleal [email protected] Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, U.K.Search for more papers by this authorBarry A. Thomas, Barry A. Thomas Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, U.K. Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, SY231NL Aberystwyth, U.K.Search for more papers by this author First published: 01 June 2018 https://doi.org/10.12705/673.33AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume67, Issue3June 2018Pages 653-654 RelatedInformation

The effect of young children's faeces disposal practices on child growth: evidence from 34 countries.

To characterize the relationship between child faeces disposal and child growth in low- and middle-income countries. We analysed caregiver responses and anthropometric data from Demographic and Health Surveys (2005-2014) for 202614 children under five and 82949 children under two to examine the association between child faeces disposal and child growth. Child faeces disposal in an improved toilet was associated with reduced stunting for children under five [adjusted prevalence ratio (aPR)=0.90, 95% confidence interval (CI) 0.89-0.92] and a 0.12 increase in height-for-age z-score (HAZ; 95% CI: 0.10-0.15) among all households. Among households with improved sanitation access, practicing improved child faeces disposal was still associated with a decrease in stunting (aPR=0.94, 95% CI: 0.91-0.96) and a 0.09 increase in HAZ (95% CI: 0.06-0.13). Improved child faeces disposal was also associated with reductions in underweight and wasting, and an increase in weight-for-age z-score (WAZ), but not an increase in weight-for-height z-score (WHZ). Community coverage level of improved child faeces disposal was also associated with stunting, with 75-100% coverage associated with the greatest reduction in stunting. Child faeces disposal in an unimproved toilet was associated with reductions in underweight and wasting, but not stunting. Improved child faeces disposal practices could achieve greater reductions in child undernutrition than improving toilet access alone. Additionally, the common classification of child faeces disposal as 'safe' regardless of the type of toilet used for disposal may underestimate the benefits of disposal in an improved toilet and overestimate the benefits of disposal in an unimproved toilet.