SYNCHRONIZATION OF STOCK PRICE AND THE ROLE OF INSTITUTIONAL INVESTORS IN TEHRAN STOCK EXCHANGE

Purpose of the study: The paper discusses the emergence of institutional investors as owners of capital in corporate governance are increasingly important. Institutional shareholders have the potential to influence management activities through an exchange of shares indirectly and directly respectively Methodology: On the basis of this study, 42 companies between the years 1389 to 1393 were studied (data for 1388 also is intended to assess the results of 1389). Results: The panel data model relationship between institutional investors with stock prices and the risk of concurrent fall in share prices was determined and it was found that institutional investors and significant negative correlation with share prices and the risk of concurrent fall in prices in the stock market Tehran. Applications of this study: This research can be used for the universities, teachers, and students. Novelty/Originality of this study: In this research, the model of Synchronization of Stock Price and the Role of Institutional Investors in the Tehran Stock Exchange is presented in a comprehensive and complete manner

The impact of financial flexibility on capital structure decisions: Some empirical evidence

This paper presents an empirical investigation to study the effect of financial flexibility on capital structure decisions on selected firms listed in Tehran Stock Exchange over the period 2006-2018. The results indicate that the cash value of the previous years had no meaningful relationship with the current year's financial leverage, which suggests that flexibility in previous years could not explain the financial leverage of the coming years and financial leverage of companies changes did not occur based on the past years performance. When the ultimate value of financial flexibility is high, the im-pact of different variables, for example, profits, depreciation, and depreciation costs, fixed assets, etc., on leverage is of little importance, with a slight change in leverage. Companies with a high final value of financial flexibility are willing to maintain their current debt capacities, but it is significantly possible that they target deliberate or temporary deviations from their leverage ratios

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Inequalities in screening policies and perioperative protection for patients with acute appendicitis during the pandemic: Subanalysis of the ACIE Appy study

N

Global attitudes in the management of acute appendicitis during COVID-19 pandemic: ACIE Appy Study

676sinoneBackground: Surgical strategies are being adapted to face the COVID-19 pandemic. Recommendations on the management of acute appendicitis have been based on expert opinion, but very little evidence is available. This study addressed that dearth with a snapshot of worldwide approaches to appendicitis. Methods: The Association of Italian Surgeons in Europe designed an online survey to assess the current attitude of surgeons globally regarding the management of patients with acute appendicitis during the pandemic. Questions were divided into baseline information, hospital organization and screening, personal protective equipment, management and surgical approach, and patient presentation before versus during the pandemic. Results: Of 744 answers, 709 (from 66 countries) were complete and were included in the analysis. Most hospitals were treating both patients with and those without COVID. There was variation in screening indications and modality used, with chest X-ray plus molecular testing (PCR) being the commonest (19·8 per cent). Conservative management of complicated and uncomplicated appendicitis was used by 6·6 and 2·4 per cent respectively before, but 23·7 and 5·3 per cent, during the pandemic (both P &lt; 0·001). One-third changed their approach from laparoscopic to open surgery owing to the popular (but evidence-lacking) advice from expert groups during the initial phase of the pandemic. No agreement on how to filter surgical smoke plume during laparoscopy was identified. There was an overall reduction in the number of patients admitted with appendicitis and one-third felt that patients who did present had more severe appendicitis than they usually observe. Conclusion: Conservative management of mild appendicitis has been possible during the pandemic. The fact that some surgeons switched to open appendicectomy may reflect the poor guidelines that emanated in the early phase of SARS-CoV-2.noneIelpo B.; Podda M.; Pellino G.; Pata F.; Caruso R.; Gravante G.; Di Saverio S.; Ielpo B.; Podda M.; Pellino G.; Pata F.; Caruso R.; Gravante G.; Di Saverio S.; Gallo G.; Lui R.; Orengia A.; Chowdary A.; Kulkarni A.; Kuvvetli A.; Navarro A.; Pisanu A.; Smith A.; Ibiricu A.C.; Nacion A.J.D.; Alsaleh A.; Alhazmi A.; Elmabri A.; Wani A.; Rencuzogullari A.; Lasarte A.S.; Rubio A.V.; Bavikatte A.; Kumar A.; Jamiri A.-R.; Padilla A.M.A.; Cacurri A.; de San Ildefonso A.; Porcu A.; Sartori A.; Rocca A.; Yanez A.P.; Becaria A.; Solis-Pena A.; Sretenovic A.; Urbistondo A.; Bandin A.; Najar A.; De Luca A.; Boddy A.; Charalabopoulos A.; Tzivanakis A.; Amendola A.; de Velasco A.R.-G.; Yildirim A.C.; Frontali A.; Toure A.O.; Garcia-Granero A.; Roldan A.M.; Larrainzar A.S.; Ratnayake A.S.; Gonzalez-Ganso A.M.; Minaya-Bravo A.M.; Das A.; Bondurri A.; Costanzi A.; 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Tolonen M.; Ciro M.P.; Zuluagua M.; Cannavo M.; Cervellera M.; Iacobone M.; Montuori M.; Podda M.; Dominguez M.G.; Bingol-Kologlu M.; Tahir M.; Lim M.; Wilson M.S.; Wilson M.; Campanelli M.; Bisaccia M.; De Rosa M.; Maruccia M.; Paterno M.; Pisano M.; Torre M.; Trevino M.; Zuolo M.; Hernandez Bartolome M.A.; Farina M.; Pera M.; Calvo M.P.; Sotelo M.; Thway M.M.; Hassan M.; Hassan M.S.E.; Azfar M.; Bouhuwaish M.; Taha M.; Zaieem M.; Korkoman M.; Guraieb M.; Shalaby M.; Raza M.A.; Younis M.U.; Elhadi M.; Ali M.Z.; Quazi N.; Dudi-Venkata N.N.; Alselaim N.; Loria N.; Ramirez N.V.; Than N.W.; Smart N.; Trelles N.; Pinto N.; Allievi N.; Petrucciani N.; Antonacci N.; Cillara N.; Gica N.; Cristiana N.D.; Krystek N.; Falco N.; Pecorelli N.; Tamini N.; Dallas N.A.; Machairas N.; Brito N.; Fieturi N.A.; Ortega N.; Mercado O.A.; Irkorucu O.; Alsherif O.; Valles O.; Ioannidis O.; Palmas O.H.; Palmas O.I.H.; Guadarrama O.S.; Bozbiyik O.; Omelanczuk P.; Ottolino P.; Rodrigues P.; Ruiz P.; Campenni P.; Chiarade P.; Olivares P.P.; Baroffio P.; Panaccio P.; Wintringer P.; Di Fronzo P.; Talento P.; Favoriti P.; Sendino P.; Marsanic P.; Mifsut P.; Andrade P.; Ajawin P.; Abadia-Barno P.; Castaneda P.A.N.; Arevalos P.O.S.; Bellver P.P.; Koh P.S.; Souza P.; Major P.; Bali R.S.; Khattar R.M.; Melo R.B.; Ebrahiminia R.; Azar R.; Murga R.L.; Caruso R.; Pirolo R.; Brady R.; Davies R.J.; Dholakia R.; Rattan R.; Singhal R.; Lim R.; Angelico R.; Isernia R.M.; Tutino R.; Faccincani R.; Peltrini R.; Carrera-Ceron R.; Tejos R.; Kashyap R.; Fajardo R.; Lozito R.; Pareja R.M.; Garbarino S.; Di Saverio S.; Morales-Conde S.; Benli S.; Mansour S.; Flores S.; Suarez S.L.; Ben S.L.; Fuentes S.; Napetti S.; de Guzman S.O.; Awad S.; Weckmann Lujan S.A.; Gentilli S.; Grimaldi S.; Pizarro S.O.; Tayar S.; Nabi S.; Chan S.M.; Junaid S.; Rojas S.; Monetti S.; Garcia S.; Salvans S.; Tenconi S.; Shaw S.; Santoni S.; Parra S.A.; Cardenas S.; Perez-Bertolez S.; Chiappetta S.; Dessureault S.; Delis S.; Bonapasta S.A.; Rausei S.; Scaringi S.; Keswani S.; Ali S.M.; Cetinkunar S.; Fung T.L.D.; Rawashdeh T.; Lopez T.N.; De Campos T.; Duque T.C.; Perra T.; Liakakos T.; Daskalakis T.; Liakakos T.; Barnes T.; Koeter T.; Zalla T.; Gonzalez T.E.; Elosua T.; Campagnaro T.; Brown T.; Luoto T.; Oumar T.A.; Giustizieri U.; Grossi U.; Bracale U.; Rivas U.; Sosa V.; Testa V.; Andriola V.; Tonini V.; Balassone V.; Celentano V.; Progno V.; Raju V.; Carroni V.; Cavallaro V.; Katta V.R.; De Simone V.; Romaguera V.P.; Orozco V.H.G.; Luraschi V.; Rachkov V.; Turrado-L V.; Visag-Castillo V.; Dowling V.; Graham V.; Papagni V.; Vigorita V.; Fonseca V.C.; Carneros V.J.; Bellato V.; Goncalves W.; Powers W.F.; Grigg W.; Bechstein W.O.; Lim Y.B.; Altinel Y.; Golubovic Z.; Balciscueta Z.Ielpo, B.; Podda, M.; Pellino, G.; Pata, F.; Caruso, R.; Gravante, G.; Di Saverio, S.; Ielpo, B.; Podda, M.; Pellino, G.; Pata, F.; Caruso, R.; Gravante, G.; Di Saverio, S.; Gallo, G.; Lui, R.; Orengia, A.; Chowdary, A.; Kulkarni, A.; Kuvvetli, A.; Navarro, A.; Pisanu, A.; Smith, A.; Ibiricu, A. C.; Nacion, A. J. D.; Alsaleh, A.; Alhazmi, A.; Elmabri, A.; Wani, A.; Rencuzogullari, A.; Lasarte, A. S.; Rubio, A. V.; Bavikatte, A.; Kumar, A.; Jamiri, A. -R.; Padilla, A. M. A.; Cacurri, A.; de San Ildefonso, A.; Porcu, A.; Sartori, A.; Rocca, A.; Yanez, A. P.; Becaria, A.; Solis-Pena, A.; Sretenovic, A.; Urbistondo, A.; Bandin, A.; Najar, A.; De Luca, A.; Boddy, A.; Charalabopoulos, A.; Tzivanakis, A.; Amendola, A.; de Velasco, A. R. -G.; Yildirim, A. C.; Frontali, A.; Toure, A. O.; Garcia-Granero, A.; Roldan, A. M.; Larrainzar, A. S.; Ratnayake, A. S.; Gonzalez-Ganso, A. M.; Minaya-Bravo, A. M.; Das, A.; Bondurri, A.; Costanzi, A.; Lucchi, A.; Mazzari, A.; Musig, A.; Peloso, A.; Piano, A.; Police, A.; Mihailescu, A.; Pouy, A.; Romano, A.; Iossa, A.; Leonetti, A. C.; Guariniello, A.; Isaac, A.; Bovi, A. P. D.; Chessa, A.; Tromba, A.; Martinez, A. A.; Brillantino, A.; Caira, A.; Castaldi, A.; Ferronetti, A.; Giuliani, A.; Prestera, A.; la Medina, A. R. -D.; Tarasconi, A.; Tornambe, A.; Picciariello, A.; Ioannidis, A.; Leppaniemi, A.; Khan, A.; Rashid, A.; Perez-Sanchez, A. L. E.; Mittal, A.; Mitul, A. R.; Mehraj, A.; Laharwal, A.; Dorisme, A.; Marinis, A.; Iqbal, A.; Moncada, A.; Braccio, B.; Alkhafaji, B.; de Andres Asenjo, B.; Martin-Perez, B.; Perez, B. S.; Creavin, B.; Cali, B.; Cali, B.; Pascotto, B.; Stubbs, B.; Retes, B. Z.; Jovanovic, B.; Goh, B. K. P.; Sensi, B.; Biddau, C.; Gazia, C.; Vallicelli, C.; Fagundes, C. A.; Santacruz, C. C.; Chirico, C.; Diaz, C. J. G.; Petrola, C.; Rodriguez, C. S.; Benitez, C. Y.; Dammaro, C.; Faro, C. L.; Reinke, C.; Paez, C. D.; Oliva, C.; Paranjape, C.; Thomas, C.; Chia, C. F.; Kong, C. K.; De Lucia, C.; Chao, C. O.; Arcudi, C.; Guerci, C.; Chia, C.; Parise, C.; Folliero, C.; Varela, C.; Ferguson, D. M.; Camacho, D.; Popowich, D.; Lima, D. S.; Rega, D.; Delogu, D.; Zigiotto, D.; Vinci, D.; D'Antonio, D.; Parini, D.; Merlini, D. A.; Zimmerman, D. D. E.; Moro-Valdezate, D.; Pertile, D.; Giusti, D. M.; Keller, D. S.; Tarik, D.; Kalivaci, D.; Mazingi, D.; Maldonado-Pintado, D. G.; Sasia, D.; Linardoutsos, D.; Osilli, D.; Murrone, D.; Russello, D.; Rodas, E.; Roa, E. A. A.; Ricciardi, E.; Rosso, E.; Saladino, E.; Flores-Villalba, E.; Ajs, E. R.; Smith-Singares, E.; Baili, E.; Kouroumpas, E.; Bourmpouteli, E.; Douka, E.; Martin-Perez, E.; Guaitoli, E.; Samadov, E.; Francone, E.; Vaterlini, E.; Morales, E.; Pena, E.; Zhao, E.; Andres, E. D. P.; Benzoni, E.; Erdas, E.; Pinotti, E.; Colas-Ruiz, E.; Aytac, E.; Laterza, E.; Agastra, E.; Foianini, E.; Moscoso, E.; Laviano, E.; Marra, E.; Cardamone, E.; Licardie, E.; Mpaili, E.; Pinna, E.; Varo, E.; Navarro, F. M.; Marino, F.; Medas, F.; Romano, F.; Maraska, F.; Saliu, F.; Madrid, F.; Rosa, F.; Mastella, F.; Gheza, F.; Luvisetto, F.; Alconchel, F.; Vieira, F. M.; Pareja, F.; Agresta, F.; Luna, F.; Bonilla, F.; Cordera, F.; Burdio, F.; Mendoza-Moreno, F.; Flores, F. M.; Aranda, F. P.; Taylor, F.; Ramos, F. L.; Fernandes, F.; Tropeano, F. P.; Balestra, F.; Bianco, F.; Ceci, F.; Colombo, F.; Di Marzo, F.; Ferrara, F.; Lancellotti, F.; Lazzarin, F.; Litta, F.; Martini, F.; Pizza, F.; Roscio, F.; Virdis, F.; Antona, F. B.; Ramirez, F. C.; Fernandez, F. M.; Llinares, F. O.; Quezada, F.; Schlottmann, F.; Quezada, F.; Herrera-Almario, G.; Massaferro, G.; Bislenghi, G.; van Ramshorst, G.; Gallo, G.; Luglio, G.; Bointas, G.; Kampouroglou, G.; Papadopoulos, G.; Manrique, G. A.; Calini, G.; Nastri, G.; Formisano, G.; Galiffa, G.; Palini, G. M.; Colucci, G.; Pagano, G.; Pellino, G.; Vanni, G.; Pattacini, G. C.; Gravante, G.; De Paola, G.; Lisi, G.; Partida, G.; Bellanova, G.; De Nobili, G.; Necchi, G. S.; Sinibaldi, G.; Tebala, G.; Bagaglini, G.; Izzo, G.; Argenio, G.; Brisinda, G.; Candilio, G.; Di Grezia, G.; Esposito, G.; Faillace, G.; Frazzetta, G.; La Gumina, G.; Nigri, G.; Romeo, G.; Amatriain, G. C.; Ortega, G.; Martin-Martin, G.; Stavrou, G. A.; Gunadi, ; Ugon, G. A.; Machain, G.; Marcucci, G.; Martinez-Mier, G.; Machain, G. M.; Nari, G.; Calvo, H.; Fathy, H.; Hamilto, ; Ahmed, H.; Faraj, H.; Nava, H.; Macias, H. O.; Nikaj, H.; Solano, H.; Khan, H. A.; Alarcon, H. S.; Ebied, H.; Giani, I.; Ateca, I. V.; Neri, I.; Roman, I. A. S.; Fidoshev, I.; Rodriguez, I. M.; Negoi, I.; Ortega, I.; Bernescu, I.; Russo, I. S.; Rodriguez, I. V.; Palomares, I.; Baltazar, I.; Torrejimeno, I. J.; Jurado, I. M. C.; Reccia, I.; Hussain, I.; Toledo, I. B.; Mora-Guzman, I.; Dogaru, I.; Romic, I.; Balciscueta, I.; Kenington, J. C.; Sagolsem, J.; Jang, J. Y.; Olivier, J.; Lammel-Lindemann, J.; Dziakova, J.; Villavicencio, J. I. R.; Salinas, J.; Parreira, J. P. J. G.; Jovanovic, ; Perez, J. R.; Reyes, J. A. S.; Luque, J. A. M.; Mak, J.; Rodriguez, J. S.; Kok, J. H. H.; Krook, J.; Diaz-Elizondo, J. A.; Castell, J.; Garcia-Flores, J. E.; Navalon, J. M. J.; Rodrigues, J. M. S.; Pereira, J.; Gomez, J. T. C.; Luque, J. B.; del Olmo, J. C. M.; Salamea, J. C.; Olivier, J. F. C.; Laina, J. L. B.; Ordonez, J. M.; Gutierrez, J.; Abba, J.; Sofi, J. A.; Sherafgan, K.; Sahnan, K.; Yanaga, K.; Beatson, K.; Asim, L.; Alvarez, L.; Siragusa, L.; Farber, L.; Ong, L.; Athanasios, L.; Garcia-Bruna, L.; De Martino, L.; Ferrario, L.; Giordano, L.; Gordini, L.; Pio, L.; Ponchietti, L.; Moletta, L.; Curella, L.; Poggi, L.; Taglietti, L.; Bonavina, L.; Conti, L.; Goffredi, L.; Ruiz, L. A. G.; Barrionuevo, L.; Fregoso, L. E.; Cabrera, L. F.; Rodriguez, L. G.; Grande, L.; Osoria, L. G.; Gonzalez, L. J. K.; Sanchez-Guillen, L.; Tallon-Aguilar, L.; Tresierra, L.; Giavarini, L.; Hasabelnabi, M.; Odovic, M.; Uemura, M.; Khan, M.; Artiles-Armas, M.; David, M.; Di Martino, M.; Spampinato, M. G.; Ribeiro, M. A. F.; Viola, M.; Angrisani, M.; Calussi, M.; Cannistra, M.; Catarci, M.; Cereda, M.; Conte, M.; Giordano, M.; Pellicciaro, M.; Marino, M. V.; Vaterlini, M. E.; Jimenez, M. F.; Lolli, M. G.; Bellini, M. I.; Lemma, M.; Chiarello, M. M.; Nicola, M.; Arrigo, M.; Mejia, M. C.; Manrique, M. M.; Rodriguez-Lopez, M.; Serradilla-Martin, M.; Lara, M. Z.; Martinez, M.; Bagnall, M.; Peter, M.; Lara, M. C.; Gomez, M. J.; Paniagua-Garcia-Senorans, M.; Gonzalez, M. P.; Rutegard, M.; Salo, M.; Franceschilli, M.; Silveri, M.; Veroux, M.; Pezzulo, M.; Nardi, M.; Rottoli, M.; Tolonen, M.; Ciro, M. P.; Zuluagua, M.; Cannavo, M.; Cervellera, M.; Iacobone, M.; Montuori, M.; Podda, M.; Dominguez, M. G.; Bingol-Kologlu, M.; Tahir, M.; Lim, M.; Wilson, M. S.; Wilson, M.; Campanelli, M.; Bisaccia, M.; De Rosa, M.; Maruccia, M.; Paterno, M.; Pisano, M.; Torre, M.; Trevino, M.; Zuolo, M.; Hernandez Bartolome, M. A.; Farina, M.; Pera, M.; Calvo, M. P.; Sotelo, M.; Thway, M. M.; Hassan, M.; Hassan, M. S. E.; Azfar, M.; Bouhuwaish, M.; Taha, M.; Zaieem, M.; Korkoman, M.; Guraieb, M.; Shalaby, M.; Raza, M. A.; Younis, M. U.; Elhadi, M.; Ali, M. Z.; Quazi, N.; Dudi-Venkata, N. N.; Alselaim, N.; Loria, N.; Ramirez, N. V.; Than, N. W.; Smart, N.; Trelles, N.; Pinto, N.; Allievi, N.; Petrucciani, N.; Antonacci, N.; Cillara, N.; Gica, N.; Cristiana, N. D.; Krystek, N.; Falco, N.; Pecorelli, N.; Tamini, N.; Dallas, N. A.; Machairas, N.; Brito, N.; Fieturi, N. A.; Ortega, N.; Mercado, O. A.; Irkorucu, O.; Alsherif, O.; Valles, O.; Ioannidis, O.; Palmas, O. H.; Palmas, O. I. H.; Guadarrama, O. S.; Bozbiyik, O.; Omelanczuk, P.; Ottolino, P.; Rodrigues, P.; Ruiz, P.; Campenni, P.; Chiarade, P.; Olivares, P. P.; Baroffio, P.; Panaccio, P.; Wintringer, P.; Di Fronzo, P.; Talento, P.; Favoriti, P.; Sendino, P.; Marsanic, P.; Mifsut, P.; Andrade, P.; Ajawin, P.; Abadia-Barno, P.; Castaneda, P. A. N.; Arevalos, P. O. S.; Bellver, P. P.; Koh, P. S.; Souza, P.; Major, P.; Bali, R. S.; Khattar, R. M.; Melo, R. B.; Ebrahiminia, R.; Azar, R.; Murga, R. L.; Caruso, R.; Pirolo, R.; Brady, R.; Davies, R. J.; Dholakia, R.; Rattan, R.; Singhal, R.; Lim, R.; Angelico, R.; Isernia, R. M.; Tutino, R.; Faccincani, R.; Peltrini, R.; Carrera-Ceron, R.; Tejos, R.; Kashyap, R.; Fajardo, R.; Lozito, R.; Pareja, R. M.; Garbarino, S.; Di Saverio, S.; Morales-Conde, S.; Benli, S.; Mansour, S.; Flores, S.; Suarez, S. L.; Ben, S. L.; Fuentes, S.; Napetti, S.; de Guzman, S. O.; Awad, S.; Weckmann Lujan, S. A.; Gentilli, S.; Grimaldi, S.; Pizarro, S. O.; Tayar, S.; Nabi, S.; Chan, S. M.; Junaid, S.; Rojas, S.; Monetti, S.; Garcia, S.; Salvans, S.; Tenconi, S.; Shaw, S.; Santoni, S.; Parra, S. A.; Cardenas, S.; Perez-Bertolez, S.; Chiappetta, S.; Dessureault, S.; Delis, S.; Bonapasta, S. A.; Rausei, S.; Scaringi, S.; Keswani, S.; Ali, S. M.; Cetinkunar, S.; Fung, T. L. D.; Rawashdeh, T.; Lopez, T. N.; De Campos, T.; Duque, T. C.; Perra, T.; Liakakos, T.; Daskalakis, T.; Liakakos, T.; Barnes, T.; Koeter, T.; Zalla, T.; Gonzalez, T. E.; Elosua, T.; Campagnaro, T.; Brown, T.; Luoto, T.; Oumar, T. 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Appendicitis risk prediction models in children presenting with right iliac fossa pain (RIFT study): a prospective, multicentre validation study.

Background Acute appendicitis is the most common surgical emergency in children. Differentiation of acute appendicitis from conditions that do not require operative management can be challenging in children. This study aimed to identify the optimum risk prediction model to stratify acute appendicitis risk in children. Methods We did a rapid review to identify acute appendicitis risk prediction models. A prospective, multicentre cohort study was then done to evaluate performance of these models. Children (aged 5\u201315 years) presenting with acute right iliac fossa pain in the UK and Ireland were included. For each model, score cutoff thresholds were systematically varied to identify the best achievable specificity while maintaining a failure rate (ie, proportion of patients identified as low risk who had acute appendicitis) less than 5%. The normal appendicectomy rate was the proportion of resected appendixes found to be normal on histopathological examination. Findings 15 risk prediction models were identified that could be assessed. The cohort study enrolled 1827 children from 139 centres, of whom 630 (34\ub75%) underwent appendicectomy. The normal appendicectomy rate was 15\ub79% (100 of 630 patients). The Shera score was the best performing model, with an area under the curve of 0\ub784 (95% CI 0\ub782\u20130\ub786). Applying score cutoffs of 3 points or lower for children aged 5\u201310 years and girls aged 11\u201315 years, and 2 points or lower for boys aged 11\u201315 years, the failure rate was 3\ub73% (95% CI 2\ub70\u20135\ub72; 18 of 539 patients), specificity was 44\ub73% (95% CI 41\ub74\u201347\ub72; 521 of 1176), and positive predictive value was 41\ub74% (38\ub75\u201344\ub74; 463 of 1118). Positive predictive value for the Shera score with a cutoff of 6 points or lower (72\ub76%, 67\ub74\u201377\ub74) was similar to that of ultrasound scan (75\ub70%, 65\ub73\u201383\ub71). Interpretation The Shera score has the potential to identify a large group of children at low risk of acute appendicitis who could be considered for early discharge. Risk scoring does not identify children who should proceed directly to surgery. Medium-risk and high-risk children should undergo routine preoperative ultrasound imaging by operators trained to assess for acute appendicitis, and MRI or low-dose CT if uncertainty remains. Funding None