{"id":"https://openalex.org/W4321787523","doi":"https://doi.org/10.3389/fams.2023.1106958","title":"A mixed effects changepoint quantile regression model for longitudinal data with application on COVID-19 data","display_name":"A mixed effects changepoint quantile regression model for longitudinal data with application on COVID-19 data","publication_year":2023,"publication_date":"2023-02-24","ids":{"openalex":"https://openalex.org/W4321787523","doi":"https://doi.org/10.3389/fams.2023.1106958"},"language":"en","primary_location":{"id":"doi:10.3389/fams.2023.1106958","is_oa":true,"landing_page_url":"http://dx.doi.org/10.3389/fams.2023.1106958","pdf_url":"https://public-pages-files-2025.frontiersin.org/journals/applied-mathematics-and-statistics/articles/10.3389/fams.2023.1106958/pdf","source":{"id":"https://openalex.org/S2597085352","display_name":"Frontiers in Applied Mathematics and Statistics","issn_l":"2297-4687","issn":["2297-4687"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310320527","host_organization_name":"Frontiers Media","host_organization_lineage":["https://openalex.org/P4310320527"],"host_organization_lineage_names":["Frontiers Media"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Frontiers in Applied Mathematics and Statistics","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","doaj"],"open_access":{"is_oa":true,"oa_status":"gold","oa_url":"https://public-pages-files-2025.frontiersin.org/journals/applied-mathematics-and-statistics/articles/10.3389/fams.2023.1106958/pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5069664483","display_name":"Wafaa Ibrahim","orcid":"https://orcid.org/0000-0001-7858-7057"},"institutions":[{"id":"https://openalex.org/I145487455","display_name":"Cairo University","ror":"https://ror.org/03q21mh05","country_code":"EG","type":"education","lineage":["https://openalex.org/I145487455"]}],"countries":["EG"],"is_corresponding":false,"raw_author_name":"Wafaa I. M. Ibrahim","raw_affiliation_strings":["Statistics Department, Faculty of Economics and Political Science, Cairo University, Giza, Egypt"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Statistics Department, Faculty of Economics and Political Science, Cairo University, Giza, Egypt","institution_ids":["https://openalex.org/I145487455"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5042542828","display_name":"Ahmed M. Gad","orcid":"https://orcid.org/0000-0002-2991-6245"},"institutions":[{"id":"https://openalex.org/I145487455","display_name":"Cairo University","ror":"https://ror.org/03q21mh05","country_code":"EG","type":"education","lineage":["https://openalex.org/I145487455"]}],"countries":["EG"],"is_corresponding":true,"raw_author_name":"Ahmed M. Gad","raw_affiliation_strings":["Statistics Department, Faculty of Economics and Political Science, Cairo University, Giza, Egypt"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Statistics Department, Faculty of Economics and Political Science, Cairo University, Giza, Egypt","institution_ids":["https://openalex.org/I145487455"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5005626038","display_name":"Abd-Elnaser S. Abd-Rabou","orcid":null},"institutions":[{"id":"https://openalex.org/I145487455","display_name":"Cairo University","ror":"https://ror.org/03q21mh05","country_code":"EG","type":"education","lineage":["https://openalex.org/I145487455"]}],"countries":["EG"],"is_corresponding":false,"raw_author_name":"Abd-Elnaser S. Abd-Rabou","raw_affiliation_strings":["Statistics Department, Faculty of Economics and Political Science, Cairo University, Giza, Egypt"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Statistics Department, Faculty of Economics and Political Science, Cairo University, Giza, Egypt","institution_ids":["https://openalex.org/I145487455"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5042542828"],"corresponding_institution_ids":["https://openalex.org/I145487455"],"apc_list":{"value":1285,"currency":"USD","value_usd":1285},"apc_paid":{"value":1285,"currency":"USD","value_usd":1285},"fwci":0.0,"has_fulltext":true,"cited_by_count":0,"citation_normalized_percentile":{"value":0.01791801,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":"9","issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10410","display_name":"COVID-19 epidemiological studies","score":0.9965000152587891,"subfield":{"id":"https://openalex.org/subfields/2611","display_name":"Modeling and Simulation"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10410","display_name":"COVID-19 epidemiological studies","score":0.9965000152587891,"subfield":{"id":"https://openalex.org/subfields/2611","display_name":"Modeling and Simulation"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10243","display_name":"Statistical Methods and Bayesian Inference","score":0.9962999820709229,"subfield":{"id":"https://openalex.org/subfields/2613","display_name":"Statistics and Probability"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10136","display_name":"Statistical Methods and Inference","score":0.9940999746322632,"subfield":{"id":"https://openalex.org/subfields/2613","display_name":"Statistics and Probability"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/quantile","display_name":"Quantile","score":0.8159038424491882},{"id":"https://openalex.org/keywords/quantile-regression","display_name":"Quantile regression","score":0.7332644462585449},{"id":"https://openalex.org/keywords/statistics","display_name":"Statistics","score":0.5391910076141357},{"id":"https://openalex.org/keywords/regression","display_name":"Regression","score":0.532416582107544},{"id":"https://openalex.org/keywords/econometrics","display_name":"Econometrics","score":0.5243644714355469},{"id":"https://openalex.org/keywords/mixed-model","display_name":"Mixed model","score":0.4702925682067871},{"id":"https://openalex.org/keywords/regression-analysis","display_name":"Regression analysis","score":0.46971267461776733},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.4440295696258545},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.40648484230041504}],"concepts":[{"id":"https://openalex.org/C118671147","wikidata":"https://www.wikidata.org/wiki/Q578714","display_name":"Quantile","level":2,"score":0.8159038424491882},{"id":"https://openalex.org/C63817138","wikidata":"https://www.wikidata.org/wiki/Q3455889","display_name":"Quantile regression","level":2,"score":0.7332644462585449},{"id":"https://openalex.org/C105795698","wikidata":"https://www.wikidata.org/wiki/Q12483","display_name":"Statistics","level":1,"score":0.5391910076141357},{"id":"https://openalex.org/C83546350","wikidata":"https://www.wikidata.org/wiki/Q1139051","display_name":"Regression","level":2,"score":0.532416582107544},{"id":"https://openalex.org/C149782125","wikidata":"https://www.wikidata.org/wiki/Q160039","display_name":"Econometrics","level":1,"score":0.5243644714355469},{"id":"https://openalex.org/C16012445","wikidata":"https://www.wikidata.org/wiki/Q1501135","display_name":"Mixed model","level":2,"score":0.4702925682067871},{"id":"https://openalex.org/C152877465","wikidata":"https://www.wikidata.org/wiki/Q208042","display_name":"Regression analysis","level":2,"score":0.46971267461776733},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.4440295696258545},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.40648484230041504}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.3389/fams.2023.1106958","is_oa":true,"landing_page_url":"http://dx.doi.org/10.3389/fams.2023.1106958","pdf_url":"https://public-pages-files-2025.frontiersin.org/journals/applied-mathematics-and-statistics/articles/10.3389/fams.2023.1106958/pdf","source":{"id":"https://openalex.org/S2597085352","display_name":"Frontiers in Applied Mathematics and Statistics","issn_l":"2297-4687","issn":["2297-4687"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310320527","host_organization_name":"Frontiers Media","host_organization_lineage":["https://openalex.org/P4310320527"],"host_organization_lineage_names":["Frontiers Media"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Frontiers in Applied Mathematics and Statistics","raw_type":"journal-article"},{"id":"pmh:oai:doaj.org/article:28bb847b51c44b6694135c569cebf409","is_oa":true,"landing_page_url":"https://doaj.org/article/28bb847b51c44b6694135c569cebf409","pdf_url":null,"source":{"id":"https://openalex.org/S4306401280","display_name":"DOAJ (DOAJ: Directory of Open Access Journals)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-sa","license_id":"https://openalex.org/licenses/cc-by-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Frontiers in Applied Mathematics and Statistics, Vol 9 (2023)","raw_type":"article"}],"best_oa_location":{"id":"doi:10.3389/fams.2023.1106958","is_oa":true,"landing_page_url":"http://dx.doi.org/10.3389/fams.2023.1106958","pdf_url":"https://public-pages-files-2025.frontiersin.org/journals/applied-mathematics-and-statistics/articles/10.3389/fams.2023.1106958/pdf","source":{"id":"https://openalex.org/S2597085352","display_name":"Frontiers in Applied Mathematics and Statistics","issn_l":"2297-4687","issn":["2297-4687"],"is_oa":true,"is_in_doaj":true,"is_core":true,"host_organization":"https://openalex.org/P4310320527","host_organization_name":"Frontiers Media","host_organization_lineage":["https://openalex.org/P4310320527"],"host_organization_lineage_names":["Frontiers Media"],"type":"journal"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Frontiers in Applied Mathematics and Statistics","raw_type":"journal-article"},"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"pdf":true,"grobid_xml":false},"content_urls":{"pdf":"https://content.openalex.org/works/W4321787523.pdf"},"referenced_works_count":28,"referenced_works":["https://openalex.org/W1511017002","https://openalex.org/W1983143923","https://openalex.org/W1985172735","https://openalex.org/W1987005168","https://openalex.org/W1998457438","https://openalex.org/W2003626243","https://openalex.org/W2015039578","https://openalex.org/W2024544539","https://openalex.org/W2037762057","https://openalex.org/W2039559768","https://openalex.org/W2049633694","https://openalex.org/W2049954089","https://openalex.org/W2070873660","https://openalex.org/W2073464636","https://openalex.org/W2084871407","https://openalex.org/W2092477801","https://openalex.org/W2094221602","https://openalex.org/W2102015455","https://openalex.org/W2584465715","https://openalex.org/W2790007761","https://openalex.org/W2902839556","https://openalex.org/W2937443283","https://openalex.org/W2944199214","https://openalex.org/W3022632670","https://openalex.org/W3105706340","https://openalex.org/W3122488737","https://openalex.org/W3198906500","https://openalex.org/W4295102658"],"related_works":["https://openalex.org/W4237949580","https://openalex.org/W2563003513","https://openalex.org/W4308624783","https://openalex.org/W1847145371","https://openalex.org/W2154247250","https://openalex.org/W2468831641","https://openalex.org/W2587147181","https://openalex.org/W2804154962","https://openalex.org/W3023065349","https://openalex.org/W4223551069"],"abstract_inverted_index":{"Introduction":[0],"Longitudinal":[1],"individual":[2],"response":[3],"profiles":[4],"could":[5],"exhibit":[6],"a":[7,65,71,91,105,242],"mixture":[8],"of":[9,14,36,42,99,130,169,202,217,249,264,288],"two":[10],"or":[11,16,26],"more":[12,27],"phases":[13],"increase":[15],"decrease":[17],"in":[18,52,81,118,125,196,253],"trend":[19],"throughout":[20],"the":[21,43,74,82,96,119,128,131,136,149,154,162,167,170,175,187,203,215,224,239,246],"follow-up":[22],"period,":[23],"with":[24,86,90,111,251],"one":[25],"unknown":[28],"transition":[29],"points":[30],"(changepoints).":[31],"The":[32,140,199,211,270],"detection":[33],"and":[34,49,161,180,190,220,261,275,285],"estimation":[35,138,189],"these":[37],"changepoints":[38,51,112],"is":[39,68,145,172,206],"crucial.":[40],"Most":[41],"proposed":[44,146,188,204],"statistical":[45],"methods":[46,80,94],"for":[47,115,258],"detecting":[48],"estimating":[50],"literature":[53,83],"rely":[54],"on":[55,214,223,245,282],"distributional":[56],"assumptions":[57],"that":[58,186],"may":[59],"not":[60],"hold.":[61],"In":[62,165],"this":[63],"case,":[64],"good":[66],"alternative":[67],"to":[69,84,113,127,147,229,235],"use":[70,201],"robust":[72],"approach;":[73],"quantile":[75,87,108,163],"regression":[76,88,109],"model.":[77],"There":[78],"are":[79,133],"deal":[85],"models":[89],"changepoint.":[92],"These":[93],"ignore":[95],"within-subject":[97],"dependence":[98,116],"longitudinal":[100,120],"data.":[101,121,210],"Methods":[102],"We":[103],"propose":[104],"mixed":[106],"effects":[107,123,151],"model":[110,205],"account":[114],"structure":[117],"Fixed":[122],"parameters,":[124],"addition":[126],"location":[129,168],"changepoint,":[132],"estimated":[134,173],"using":[135,174,208],"profile":[137],"method.":[139],"stochastic":[141],"approximation":[142],"EM":[143],"algorithm":[144],"estimate":[148],"fixed":[150],"parameters":[152],"exploiting":[153],"link":[155],"between":[156],"an":[157],"asymmetric":[158],"Laplace":[159],"distribution":[160],"regression.":[164],"addition,":[166],"changepoint":[171],"usual":[176],"optimization":[177],"methods.":[178],"Results":[179],"discussion":[181],"A":[182],"simulation":[183],"study":[184],"shows":[185],"inferential":[191],"procedures":[192],"perform":[193],"reasonably":[194],"well":[195],"finite":[197],"samples.":[198],"practical":[200],"illustrated":[207],"COVID-19":[209,230,252],"data":[212],"focus":[213],"effect":[216,244,281],"global":[218],"economic":[219],"health":[221],"factors":[222],"monthly":[225,247,266,290],"death":[226],"rate":[227],"due":[228],"from":[231],"1":[232],"April":[233,237],"2020":[234],"30th":[236],"2021.":[238],"results":[240],"show":[241],"positive":[243],"number":[248],"patients":[250],"intensive":[254],"care":[255],"units":[256],"(ICUs)":[257],"both":[259,283],"0.5th":[260,284],"0.8th":[262,286],"quantiles":[263,287],"new":[265,289],"deaths":[267,291],"per":[268,292],"million.":[269,293],"stringency":[271],"index,":[272],"hospital":[273],"beds,":[274],"diabetes":[276],"prevalence":[277],"have":[278],"no":[279],"significant":[280]},"counts_by_year":[],"updated_date":"2026-07-23T08:03:31.855105","created_date":"2025-10-10T00:00:00"}