{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T15:03:02Z","timestamp":1775833382627,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,3,27]],"date-time":"2025-03-27T00:00:00Z","timestamp":1743033600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Healthcare"],"abstract":"<jats:p>Background\/Objectives: Long waiting times for outpatient care remain a global challenge for public health systems. In Portugal, the National Health Service (NHS) ensures universal access to medical treatment, aiming to promote equity in healthcare. However, persistent delays in outpatient speciality appointments hinder this objective. Methods: This study proposes a prioritization-scheduling approach that integrates a mathematical model with a heuristic method to enhance accessibility in NHS hospitals. By optimizing the available capacity of hospitals within each geographic area, the model efficiently sequences patient appointments across different facilities, prioritizing those who have waited the longest. The approach was tested using simulated instances based on real NHS hospital data. Results: Results indicate that the model effectively integrates hospital resources within a region and efficiently allocates specialist appointments, significantly reducing waiting times. Conclusions: This research introduces a promising strategy that, when incorporated into a decision support system, can serve as a valuable tool for healthcare management.<\/jats:p>","DOI":"10.3390\/healthcare13070749","type":"journal-article","created":{"date-parts":[[2025,3,28]],"date-time":"2025-03-28T06:45:51Z","timestamp":1743144351000},"page":"749","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["A Scheduling Optimization Approach to Reduce Outpatient Waiting Times for Specialists"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4687-2747","authenticated-orcid":false,"given":"Ana","family":"Moura","sequence":"first","affiliation":[{"name":"Department of Economics, Management and Industrial Engineering and Tourism, University of Aveiro, Campo Universit\u00e1rio De Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2021-9141","authenticated-orcid":false,"given":"Micaela","family":"Pinho","sequence":"additional","affiliation":[{"name":"Research on Economics, Management and Information Technologies, Portucalense University, R. Dr. Ant\u00f3nio Bernardino de Almeida 541, 4200-072 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1093\/bmb\/ldq014","article-title":"Policy Strategies to Reduce Waits for Elective Care: A Synthesis of International Evidence","volume":"95","author":"Kreindler","year":"2010","journal-title":"Br. Med. Bull."},{"key":"ref_2","unstructured":"INE\u2014Instituto Nacional de Estat\u00edstica (2022, June 02). Statistics Portugal Database. Available online: https:\/\/www.ine.pt\/xportal\/xmain?xpid=INE&xpgid=ine_main."},{"key":"ref_3","unstructured":"OECD\u2014European Observatory on Health Systems and Policies (2023). Portugal: Country Health Profile 2023, European Observatory on Health Systems and Policies."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1203","DOI":"10.1016\/j.healthpol.2017.09.010","article-title":"Introduction of freedom of choice for hospital outpatient care in Portugal: Implications and results of the 2016 reform","volume":"121","author":"Augusto","year":"2017","journal-title":"Health Policy"},{"key":"ref_5","unstructured":"SNS (2019) Relat\u00f3rio Anual (2022, June 02). Acesso a Cuidados de Sa\u00fade nos Estabelecimentos do SNS e Entidades Convencionadas. Minist\u00e9rio da Sa\u00fade., Available online: https:\/\/direitodamedicina.sanchoeassociados.com\/arquivo\/relatorio-anual-acesso-a-cuidados-de-saude-nos-estabelecimentos-do-sns-e-entidades-convencionadas-acss\/."},{"key":"ref_6","unstructured":"ERS (2022, June 02). Entidade Reguladora da Sa\u00fade. Informa\u00e7\u00e3o de Monitoriza\u00e7\u00e3o Sobre Tempos de Espera no SNS\u2014Primeiro e Segundo Semestre de 2019. Porto, Portugal. Available online: https:\/\/www.ers.pt\/media\/3633\/info-monit-tempos-espera-ano-2019_nv.pdf."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2463483","DOI":"10.1080\/10872981.2025.2463483","article-title":"CARAvELA\u2014Competency in Anaesthesiology\u2014Self-Reported Assessment on European Learning Aims: A National Survey","volume":"30","author":"Oliveira","year":"2025","journal-title":"Med. Educ. Online"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1300\/J026v23n02_05","article-title":"The impact of unacceptable wait time on health care patients\u2019 attitudes and actions","volume":"23","author":"Hill","year":"2005","journal-title":"Health Mark. Q."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.socscimed.2016.05.043","article-title":"Do waiting times affect health outcomes? Evidence from coronary bypass","volume":"161","author":"Moscelli","year":"2016","journal-title":"Soc. Sci. Med."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Johannesson, K., and Alexandersen, N. (2018). Improving accessibility for outpatients in specialist clinics: Reducing long waiting times and waiting lists with a simple analytic approach. BMC Health Serv. Res., 18.","DOI":"10.1186\/s12913-018-3635-3"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1071\/AH16275","article-title":"Time to wait: A systematic review of strategies that affect out-patient waiting times","volume":"42","author":"Naiker","year":"2018","journal-title":"Aust. Health Rev."},{"key":"ref_12","first-page":"31","article-title":"Is follow-up capacity the current NHS bottleneck","volume":"11","author":"Allder","year":"2011","journal-title":"Clin. Med. J. R. Coll. Phys. Lond."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Aragon, M.J.A., Castelli, A., and Gaughan, J. (2017). Hospital Trusts productivity in the English NHS: Uncovering possible drivers of productivity variations. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0182253"},{"key":"ref_14","unstructured":"FFMS (2022, June 02). Consultas Externas Nos Hospitais: Total e por Algumas Especialidades M\u00e9dicas, Paris: PORDATA. Available online: https:\/\/www.pordata.pt\/sites\/default\/files\/2024-06\/Municipios_Consultas_externas_nos_hospitais__total_e_por_algumas_especialidades_medicas.xlsx."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1017\/S174413311400022X","article-title":"Improving productive efficiency in hospitals: Findings from a review of the international evidence","volume":"10","author":"Rumbold","year":"2015","journal-title":"Health Econ. Policy Law"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Brandeau, M., Sainfort, F., and Pierskalla, W. (2004). Operations Research and Health Care: A Handbook of Methods and Applications, Springer.","DOI":"10.1007\/b106574"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1057\/jors.2009.14","article-title":"One hundred years of Operational Research in Health\u2014UK, 1948\u20132048","volume":"60","author":"Royston","year":"2009","journal-title":"J. Oper. Res. Soc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1563","DOI":"10.1057\/palgrave.jors.2602315","article-title":"A multi-objective model to determine efficient resource levels in a medical assessment unit","volume":"58","author":"Oddoye","year":"2007","journal-title":"J. Oper. Res. Soc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.orhc.2013.12.001","article-title":"Scheduling elective surgeries in a Portuguese hospital using a genetic heuristic","volume":"3","author":"Marques","year":"2014","journal-title":"Oper. Res. Health Care"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.orhc.2015.09.009","article-title":"Aggregate capacity planning for elective surgeries: A bi-objective optimization approach to balance patients waiting with healthcare costs","volume":"7","author":"Malik","year":"2015","journal-title":"Oper. Res. Health Care"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1007\/s10729-020-09528-y","article-title":"A robust optimization model for tactical capacity planning in an outpatient setting","volume":"24","author":"Aslani","year":"2020","journal-title":"Health Care Manag. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.ejor.2007.10.029","article-title":"Combining simulation and goal programming for healthcare planning in a medical assessment unit","volume":"193","author":"Oddoye","year":"2009","journal-title":"Eur. J. Oper. Res."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Heshmat, M., Mostafa, N., and Park, J. (2017, January 4\u20137). Towards patient-oriented design: A case of the Egyptian private outpatient clinics. Proceedings of the 50th Hawaii International Conference on System Sciences, Waikoloa Village, HI, USA.","DOI":"10.24251\/HICSS.2017.464"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"9034737","DOI":"10.1155\/2017\/9034737","article-title":"Resource Allocation and Outpatient Appointment Scheduling Using Simulation Optimization","volume":"2017","author":"Lin","year":"2017","journal-title":"J. Healthc. Eng."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Lee, C.K.M., Ng, K.K.H., and Cheng, M.C. (2018, January 26\u201327). Appointment Scheduling Optimization for Specialist Outpatient Services. Proceedings of the 2nd European Conference on Industrial Engineering and Operations Management (IEOM), Paris, France.","DOI":"10.1111\/poms.12791"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1016\/j.cie.2018.07.033","article-title":"Solving the patient appointment scheduling problem in outpatient chemotherapy clinics using clustering and mathematical programming","volume":"124","author":"Heshmat","year":"2018","journal-title":"Comput. Ind. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/j.eswa.2018.02.022","article-title":"Optimizing outpatient appointment system using machine learning algorithms and scheduling rules: A prescriptive analytics framework","volume":"102","author":"Srinivas","year":"2018","journal-title":"Expert Syst. Appl."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1007\/s10479-019-03500-y","article-title":"Solving operational problems in outpatient chemotherapy clinics using mathematical programming and simulation","volume":"298","author":"Heshmat","year":"2021","journal-title":"Ann. Oper. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1080\/01605682.2019.1700186","article-title":"A novel healthcare resource allocation decision support tool: A forecasting-simulation optimization approach","volume":"72","author":"Ordu","year":"2021","journal-title":"J. Oper. Res. Soc."},{"key":"ref_30","first-page":"100","article-title":"Assessing the impact of patient prioritization on operating room schedules","volume":"24","author":"Oliveira","year":"2020","journal-title":"Oper. Res. Health Care"}],"container-title":["Healthcare"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9032\/13\/7\/749\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:03:28Z","timestamp":1760029408000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9032\/13\/7\/749"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,27]]},"references-count":30,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["healthcare13070749"],"URL":"https:\/\/doi.org\/10.3390\/healthcare13070749","relation":{},"ISSN":["2227-9032"],"issn-type":[{"value":"2227-9032","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,27]]}}}