{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T21:11:35Z","timestamp":1790629895903,"version":"4.1.0"},"reference-count":44,"publisher":"European Respiratory Society (ERS)","issue":"3","license":[{"start":{"date-parts":[[2025,3,28]],"date-time":"2025-03-28T00:00:00Z","timestamp":1743120000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["publications.ersnet.org"],"crossmark-restriction":true},"short-container-title":["ERJ Open Res"],"accepted":{"date-parts":[[2024,12,10]]},"published-print":{"date-parts":[[2025,5]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      The extent to which changes in lung function are due to natural variability in patients with primary ciliary dyskinesia (PCD) is unknown. We aimed to assess intra-individual variability in forced expiratory volume in 1\u2005s (FEV\n                      <jats:sub>1<\/jats:sub>\n                      ) derived from spirometry to define the extent to which the observed changes were due to test variability in clinically stable PCD patients.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      PROVALF-PCD (Prospective Observational Multicentre Study on Variability of Lung Function in Stable PCD Patients) was a large international prospective cohort conducted in 2017\u20132019. We included patients aged \u22655\u2005years who were clinically stable at two or more consecutive visits and provided spirometry-derived lung function measurements. To calculate the upper limit of normal (ULN), we fitted an unadjusted multilevel mixed-effect model, and to determine the absolute change in FEV\n                      <jats:sub>1<\/jats:sub>\n                      z-scores, we calculated the coefficient of repeatability (CR). We performed sensitivity analyses by stratifying relative change by age (adults\n                      <jats:italic>versus<\/jats:italic>\n                      children), number of measurements (at least four), and time between measurements (&lt;4\u2005months apart).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      We included 252 participants from 12 countries with confirmed or highly likely PCD. We included 1028 FEV\n                      <jats:sub>1<\/jats:sub>\n                      measurements from patients in stable state. The ULN for relative change between two measurements of FEV\n                      <jats:sub>1<\/jats:sub>\n                      was 25%. Test variability remained high in all sensitivity analyses. The CR was 1.88 FEV\n                      <jats:sub>1<\/jats:sub>\n                      z-score.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>\n                      Changes in intra-individual FEV\n                      <jats:sub>1<\/jats:sub>\n                      &gt;25% between visits in stable PCD patients lie beyond the expected test variability and therefore could be considered physiologically relevant. These findings inform the selection of end-points for pulmonary intervention trials in PCD, as they suggest that FEV\n                      <jats:sub>1<\/jats:sub>\n                      is not a sensitive test for monitoring lung health in PCD.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1183\/23120541.01115-2024","type":"journal-article","created":{"date-parts":[[2025,3,28]],"date-time":"2025-03-28T08:19:07Z","timestamp":1743149947000},"page":"01115-2024","update-policy":"https:\/\/doi.org\/10.1183\/ers-crossmark-policy","source":"Crossref","is-referenced-by-count":8,"title":["Natural variability of lung function in primary ciliary dyskinesia: longitudinal analysis from the PROVALF-PCD cohort"],"prefix":"10.1183","volume":"11","author":[{"given":"Kewei","family":"Zhang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Avni","family":"Kant","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mieke","family":"Boon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melissa","family":"Borrelli","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6596-1596","authenticated-orcid":false,"given":"Carolina","family":"Constant","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0121-2676","authenticated-orcid":false,"given":"Silvia","family":"Castillo Corullon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7711-5672","authenticated-orcid":false,"given":"Renato","family":"Cutrera","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6020-8717","authenticated-orcid":false,"given":"Stefanie","family":"Dillenh\u00f6fer","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sanem","family":"Ery\u0131lmaz Polat","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ela","family":"Eralp","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nathalie","family":"Feyaerts","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6953-7370","authenticated-orcid":false,"given":"Amanda","family":"Harris","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claire","family":"Hogg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cordula","family":"Koerner-Rettberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Panayiotis","family":"Kouis","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Enrico","family":"Lombardi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2653-5885","authenticated-orcid":false,"given":"Natalie","family":"Lorent","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4420-3091","authenticated-orcid":false,"given":"June K.","family":"Marthin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vendula","family":"Martinu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"Moreno-Galdo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6389-1953","authenticated-orcid":false,"given":"Lucy","family":"Morgan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kim","family":"Nielsen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0282-6765","authenticated-orcid":false,"given":"Heymut","family":"Omran","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ugur","family":"Ozcelik","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4557-2515","authenticated-orcid":false,"given":"Petr","family":"Pohunek","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6129-9075","authenticated-orcid":false,"given":"Phil","family":"Robinson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9896-0621","authenticated-orcid":false,"given":"Sandra","family":"Rovira-Amigo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9375-7429","authenticated-orcid":false,"given":"Francesca","family":"Santamaria","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6737-3624","authenticated-orcid":false,"given":"Anne","family":"Schlegtendal","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aline","family":"Tamalet","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0528-5458","authenticated-orcid":false,"given":"Guillaume","family":"Thouvenin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dilber","family":"Ademhan Tural","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicola","family":"Ullmann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Woolf T.","family":"Walker","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Panayiotis","family":"Yiallouros","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Camille","family":"Pearse","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bettina","family":"Frauchiger","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8957-2002","authenticated-orcid":false,"given":"Claudia E.","family":"Kuehni","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6417-382X","authenticated-orcid":false,"given":"Nicole","family":"Beydon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5239-1571","authenticated-orcid":false,"given":"Philipp","family":"Latzin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8701-9975","authenticated-orcid":false,"given":"Jane S.","family":"Lucas","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1629-8601","authenticated-orcid":false,"given":"Bruna","family":"Rubbo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"81","published-online":{"date-parts":[[2025,3,28]]},"reference":[{"key":"2025062304002046000_11.3.01115-2024.1","doi-asserted-by":"publisher","DOI":"10.1080\/17476348.2017.1360770"},{"key":"2025062304002046000_11.3.01115-2024.2","doi-asserted-by":"publisher","DOI":"10.1136\/adc.2006.096958"},{"key":"2025062304002046000_11.3.01115-2024.3","doi-asserted-by":"publisher","DOI":"10.1183\/13993003.01795-2015"},{"key":"2025062304002046000_11.3.01115-2024.4","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.05.00035205"},{"key":"2025062304002046000_11.3.01115-2024.5","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.98.11030787"},{"key":"2025062304002046000_11.3.01115-2024.6","doi-asserted-by":"publisher","DOI":"10.1183\/13993003.01499-2021"},{"key":"2025062304002046000_11.3.01115-2024.7","doi-asserted-by":"publisher","DOI":"10.1164\/rccm.200811-1731OC"},{"key":"2025062304002046000_11.3.01115-2024.8","doi-asserted-by":"publisher","DOI":"10.1183\/13993003.01040-2018"},{"key":"2025062304002046000_11.3.01115-2024.9","doi-asserted-by":"publisher","DOI":"10.1164\/rccm.201803-0548OC"},{"key":"2025062304002046000_11.3.01115-2024.10","doi-asserted-by":"publisher","DOI":"10.1136\/thoraxjnl-2014-206578"},{"key":"2025062304002046000_11.3.01115-2024.11","doi-asserted-by":"publisher","DOI":"10.1513\/AnnalsATS.201712-967OC"},{"key":"2025062304002046000_11.3.01115-2024.12","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/S2213-2600(23)00226-6","article-title":"Safety and efficacy of the epithelial sodium channel blocker idrevloride in people with primary ciliary dyskinesia (CLEAN-PCD): a multinational, phase 2, randomised, double-blind, placebo-controlled crossover trial","volume":"12","author":"Ringshausen","year":"2024","journal-title":"Lancet Respir Med"},{"key":"2025062304002046000_11.3.01115-2024.13","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/S2213-2600(20)30058-8","article-title":"Efficacy and safety of azithromycin maintenance therapy in primary ciliary dyskinesia (BESTCILIA): a multicentre, double-blind, randomised, placebo-controlled phase 3 trial","volume":"8","author":"Kobbernagel","year":"2020","journal-title":"Lancet Respir Med"},{"key":"2025062304002046000_11.3.01115-2024.14","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1186\/s12919-016-0067-0","article-title":"Proceedings of the COST action BM1407 inaugural conference BEAT-PCD: translational research in primary ciliary dyskinesia \u2013 bench, bedside, and population perspectives","volume":"10","author":"Rubbo","year":"2016","journal-title":"BMC Proc"},{"key":"2025062304002046000_11.3.01115-2024.15","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s12919-018-0098-9","article-title":"Proceedings of the 2nd BEAT-PCD conference and 3rd PCD training school: part 1","volume":"12","author":"Halbeisen","year":"2018","journal-title":"BMC Proc"},{"key":"2025062304002046000_11.3.01115-2024.16","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1186\/s12919-018-0161-6","article-title":"Proceedings of the 3rd BEAT-PCD conference and 4th PCD training school","volume":"12","author":"Farley","year":"2018","journal-title":"BMC Proc"},{"key":"2025062304002046000_11.3.01115-2024.17","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1186\/s12919-020-00191-3","article-title":"Proceedings of the 4th BEAT-PCD conference and 5th PCD training school","volume":"14","author":"Gardner","year":"2020","journal-title":"BMC Proc"},{"key":"2025062304002046000_11.3.01115-2024.18","doi-asserted-by":"publisher","DOI":"10.1183\/13993003.01090-2016"},{"key":"2025062304002046000_11.3.01115-2024.19","doi-asserted-by":"publisher","DOI":"10.1183\/13993003.00725-2019"},{"key":"2025062304002046000_11.3.01115-2024.20","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbi.2019.103208"},{"key":"2025062304002046000_11.3.01115-2024.21","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbi.2008.08.010"},{"key":"2025062304002046000_11.3.01115-2024.22","doi-asserted-by":"publisher","DOI":"10.1183\/23120541.00253-2024"},{"key":"2025062304002046000_11.3.01115-2024.23","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.05.00034805"},{"key":"2025062304002046000_11.3.01115-2024.24","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.00080312"},{"key":"2025062304002046000_11.3.01115-2024.25","unstructured":"World Health Organization (WHO) . BMI-for-age (5\u201319 years). www.who.int\/tools\/growth-reference-data-for-5to19-years\/indicators\/bmi-for-age"},{"key":"2025062304002046000_11.3.01115-2024.26","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0073990"},{"key":"2025062304002046000_11.3.01115-2024.27","first-page":"365","article-title":"Evaluating lung function and anthropometric growth data in a longitudinal study on adolescents","volume":"56","author":"Schrader","year":"1984","journal-title":"Hum Biol"},{"key":"2025062304002046000_11.3.01115-2024.28","first-page":"974","article-title":"Longitudinal changes in forced expiratory volume in one second in adults. Methodologic considerations and findings in healthy nonsmokers","volume":"133","author":"Burrows","year":"1986","journal-title":"Am Rev Respir Dis"},{"key":"2025062304002046000_11.3.01115-2024.29","doi-asserted-by":"publisher","DOI":"10.1136\/thoraxjnl-2020-214817"},{"key":"2025062304002046000_11.3.01115-2024.30","doi-asserted-by":"publisher","DOI":"10.1164\/ajrccm\/144.5.1202"},{"key":"2025062304002046000_11.3.01115-2024.31","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199409083311003"},{"key":"2025062304002046000_11.3.01115-2024.32","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.jpeds.2015.08.042","article-title":"Forced expiratory volume in 1\u2005second variability helps identify patients with cystic fibrosis at risk of greater loss of lung function","volume":"169","author":"Morgan","year":"2016","journal-title":"J Pediatr"},{"key":"2025062304002046000_11.3.01115-2024.33","doi-asserted-by":"publisher","DOI":"10.1183\/23120541.00115-2023"},{"key":"2025062304002046000_11.3.01115-2024.34","doi-asserted-by":"crossref","first-page":"1085","DOI":"10.1513\/AnnalsATS.201905-375OC","article-title":"Comparison of multiple breath washout and spirometry in children with primary ciliary dyskinesia and cystic fibrosis and healthy controls","volume":"17","author":"Kinghorn","year":"2020","journal-title":"Ann Am Thorac Soc"},{"key":"2025062304002046000_11.3.01115-2024.35","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1016\/j.jcf.2023.05.011","article-title":"Quantifying variation in home spirometry in people with cystic fibrosis during baseline health, and associations with clinical outcomes","volume":"23","author":"Thornton","year":"2024","journal-title":"J Cyst Fibros"},{"key":"2025062304002046000_11.3.01115-2024.36","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.jcf.2021.08.013","article-title":"A comparison of clinic and home spirometry as longtudinal outcomes in cystic fibrosis","volume":"21","author":"Paynter","year":"2022","journal-title":"J Cyst Fibros"},{"key":"2025062304002046000_11.3.01115-2024.37","doi-asserted-by":"publisher","DOI":"10.1001\/jama.290.13.1749"},{"key":"2025062304002046000_11.3.01115-2024.38","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-024-49150-y"},{"key":"2025062304002046000_11.3.01115-2024.39","doi-asserted-by":"crossref","first-page":"943","DOI":"10.1016\/j.jcf.2024.07.005","article-title":"Impact of day-to-day variation in FEV1 on measures of change: a conceptual description","volume":"23","author":"Magaret","year":"2024","journal-title":"J Cyst Fibros"},{"key":"2025062304002046000_11.3.01115-2024.40","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1002\/ppul.26180","article-title":"Variability of clinically measured lung clearance index in children with cystic fibrosis","volume":"58","author":"Frauchiger","year":"2023","journal-title":"Pediatr Pulmonol"},{"key":"2025062304002046000_11.3.01115-2024.41","doi-asserted-by":"crossref","first-page":"242","DOI":"10.1016\/j.jcf.2017.11.007","article-title":"Variability of monthly nitrogen multiple-breath washout during one year in children with cystic fibrosis","volume":"17","author":"Green","year":"2018","journal-title":"J Cyst Fibros"},{"key":"2025062304002046000_11.3.01115-2024.42","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.jcf.2017.08.004","article-title":"Variability of lung clearance index in clinically stable cystic fibrosis lung disease in school age children","volume":"17","author":"Svedberg","year":"2018","journal-title":"J Cyst Fibros"},{"key":"2025062304002046000_11.3.01115-2024.43","doi-asserted-by":"publisher","DOI":"10.1136\/thoraxjnl-2020-215504"},{"key":"2025062304002046000_11.3.01115-2024.44","doi-asserted-by":"publisher","DOI":"10.1183\/23120541.00147-2018"}],"container-title":["ERJ Open Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1183\/23120541.01115-2024","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,23]],"date-time":"2025-06-23T07:00:33Z","timestamp":1750662033000},"score":1,"resource":{"primary":{"URL":"https:\/\/publications.ersnet.org\/lookup\/doi\/10.1183\/23120541.01115-2024"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,28]]},"references-count":44,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2025,6,23]]},"published-print":{"date-parts":[[2025,5]]}},"alternative-id":["10.1183\/23120541.01115-2024"],"URL":"https:\/\/doi.org\/10.1183\/23120541.01115-2024","relation":{},"ISSN":["2312-0541"],"issn-type":[{"value":"2312-0541","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,28]]}}}