• Long term follow-up after extremely preterm birth.
    Main focus: Respiratory and exercise physiology.
    Additional foci: Quality of life research, pain issues, infant lung function testing,
    acquisition of normal values.

  • Long-term follow-up after severe bronchiolitis.
    Main focus: respiratory physiology.

  • Exercise induced breathing difficulties,
    Particularly focused on exercise induced laryngeal obstructions (EILO)



Director; Medicines for Children Network, Norway
A nationwide network, engaged in pediatric use of medicinal products, financed annually over the State Budget, EUR 600.000, employing 20 people (all part-time, approximately 5 FTEs), engaging approximately 100 clinicians. Annual number of “clicks” of internet site is exceeding 100.000.

Director; Medicines for Children Research Network Norway (NorPedMed)
A nationwide network constructed in 2013 by Medicines for Children Network, Norway to facilitate medicinal clinical trials in children in Norway. Annual budget EUR 0.1 million.

Nordic investigators network for pediatric medicines (NordicPedMed). Co-initiator with Kalle Hoppu at FinPedMed, and presently member of steering committee. A research network, run by clinicians, aiming to facilitate medicinal clinical trials in children, financed by the Nordic Council, currently via a NOK 250.000 grant.

Partner; European Pediatric Clinical Trial Infrastructure Network (EPCTRI), later called “PedCRIN
A European research network, run by clinicians, aiming to facilitate medicinal clinical trials in children.
PedCRIN was successfully awarded a Horizon 2020 EUR 3 mill grant in 2016. NorPedMed will host PedCRINs annual European meeting April 2018

Partner; Collaborative Network for European Clinical Trials for Children (CONECT4Children or C4C).
C4C is currently the only shortlisted, and thus the only realistic applicant to the EC IMI2-2016-10-04 call, total value EUR 130 mill.

Contractor (with NTNU); Research on European Cohorts of Children and Adults born Preterm (RECAP). RECAP was granted EU Horizon 2020 financing September 2016.

Partner; Adults Born Preterm International Collaboration (APIC), aiming to expand the understanding of adult outcomes of preterm birth by world wide pooling of data, led by the Murdoch Children’s Research Institute.

Head of Task Force - European Respiratory Society (ERS) TF-2010-01 on Inducible Laryngeal Obstructions (ILO). A joint European Respiratory and Laryngological Society (ERS and ELS) and American College of Chest Physician (ACCP) Task Force aiming to define taxonomical standards, evaluate current literature and direct future research. The nomenclature statement was published in 2015 (ERR), and the State-of-the-art article September 2017 (ERJ).

European Respiratory Society (ERS) TF-2015-18 Long term management of bronchopulmonary dysplasia (BPD). Board member. This ERS initiative aims to construct evidence based strategies for follow-up after neonatal BPD, which is currently the most common chronic pulmonary disorder in children. The Task Force met for discussions of the proceedings at the ERS in London, September 2016.

EXTRASTIFTELSEN Research Foundation. Review board for research since 2013. This is a private foundation, handling annually approximately 300 applications and allocating annually EUR 8-10 million to research.

Head; Clinical activities and one of two initiators of the “Energy-centre” in Bergen
A new EUR 30 million center for physical activity, exercise and sports for young people with special needs, opening March 2017, with more than ½ of investments raised through private donations.

Head of the “Research group for respiratory and exercise physiology” in Bergen since 2006
Activities have mainly been funded through PhD and postdoctor scholarships, with grants covering 7 completed and 5 ongoing PhD projects and 2 ongoing postdoctor projects, average costs approximately NOK 1 million per FTE. In 2015 the group was awarded a 5 year infrastructure grant from Western Norway Health Authority, in total NOK 7.5 mill.

Associate Editor for pediatrics in “Clinical Respiratory Journal” since 2007 until Wiley sold the journal to new Chinese owners 2011/2012.

Board member; Postgraduate School of Clinical Medical Research, University of Bergen since 2014

Board member; Norwegian Medical Association specialty board since 2015


Supervisor PhD
* Completed PhD : Robert Maat (2011); Ola Røksund (2012); Ingvild Bruun Mikalsen (2014); Bente   
   Vederhus (2015); Hege Havstad Clemm (2015); Maria Vollsæter (2016)
* Ongoing PhD: Tiina Andersen; Mariann Bentsen; Lars Tveiten; Merete Engeseth; Astrid Sandnes;
    Ingrid Kuiper

Peer reviews - journal articles (alphabetical): Acta Paediatrica; American Journal of Respiratory and Critical Care Medicine; Annals of the American Thoracic Society; Archives of Disease in Childhood; Clinical Respiratory Journal (Associate Editor); European Respiratory Journal; European Respiratory Reviews; JAMA Pediatrics; Journal of Pediatrics; PlosOne; Pediatrics; Pediatric Pulmonology; Respiratory Medicine; Thorax.

Peer reviews - grant applications: King’s College Health Partner’s Research and Development Challenge Fund (London, UK; 2014); Medical Research Council (London, UK; 3 grants in 2015 and 2016 and 2016); Raine Medical Research Foundation (Perth, Western Australia; 2 grants in 2006 and partly 2016); Welcome Foundation (London UK; 2013); EXTRASTIFTELSEN (see above)

Evaluation committees/boards: Three PhD dissertations (at the Universities of Tromsø and Bergen and at Karolinska Institute, Stockholm Sweden), two postdoctor positions (University of Bergen), one professor position (University of Oslo), master degree evaluations at the Norwegian School of Sports Sciences spring 2012-2015 (four), and midway evaluations at the University of Bergen since 2012 (approximately 10).


Publication list since 2000



1. Eosinophil counts and urinary eosinophil protein X in children hospitalized for wheezing during the first year of life: prediction of recurrent wheezing. Oymar K, Havnen J, Halvorsen T, and Bjerknes R.
Acta Paediatrica, 2001 Aug;90(8):843-9.


2. Pulmonary outcome in adolescents of extreme preterm birth: a regional cohort study. Halvorsen T, Skadberg BT, Eide GE, Røksund OD, Carlsen KH, and Bakke P. Acta Paediatrica, 2004; 93: 1294-300.


3. Assessment of lung volumes in children and adolescents: comparison of two plethysmographic techniques. Halvorsen T, Skadberg BT, Eide GE, Røksund OD, Bakke P, and Thorsen E.
Clin Physiol Funct Imaging, 2005;25:62-8.

4. Characteristics of asthma and airway hyper-responsiveness after premature birth. Halvorsen T, Skadberg BT, Eide GE, Røksund OD, Aksnes L, and Øymar K.  Pediatric Allergy Immunol., 2005; 16: 487-494.


5. Continuous laryngoscopy exercise test: a method for visualizing laryngeal dysfunction during exercise. Heimdal, JH, Roksund O, Halvorsen T, Skadberg BT, and Olofsson J.
Laryngoscope, 2006 Jan;116(1):52-7.

6. Mast cell activation and leukotriene secretion in wheezing infants. Relation to outcome.
Øymar K, Halvorsen T, and Aksnes L. Pediatric Allergy Immunology, 2006 Feb;17(1):37-42.

7. Better care of immature infants, has it influenced long-term pulmonary outcome? Halvorsen, T, Skadberg BT, Eide GE, Røksund OD, and Markestad T. Acta Paediatrica, 2006 May; 95(5):547-54.

8. High-resolution CT in ex-premature children.

Aukland SM, Halvorsen T, Fosse KR, Daltveit AK, and Rosendahl K.

American Journal of Roentgenology, 2006 Oct;187(4):1012-8.



9. Surgical treatment of exercise-induced laryngeal dysfunction.

Maat RC, Roksund OD, Olofsson J, Halvorsen T, Skadberg BT, and Heimdal JH.

Eur Arch Otorhinolaryngol. 2007 Apr; 264(4):401-7. Epub 2007 Jan 4.

Continuous Laryngoscopy Exercise Test.                                               

10. Heimdal, JH, Roksund OD, Halvorsen T, Skadberg BT, and Olofsson J.

Laryngoscope, 2007 Aug; 117(8):1509-10.           



11. A novel mitochondrial ND5 (MTND5) gene mutation giving isolated exercise intolerance.
Downham E, Winterthun S, Nakkestad HL, Hirth A, Halvorsen T, Taylor R, Bindoff LA.
Neuromuscular Disorders. 2008 April;18(4):310-4.


12. Neonatal bronchopulmonary dysplasia predicts abnormal pulmonary HRCT in long term survivors of extreme preterm birth. Aukland SM, Rosendahl K, Owens CM, Fosse K, Eide GE, and Halvorsen T. Thorax. 2009, Jan 21. Volum 64.(5) s. 405-410


13. Emergency presentation and management of acute severe asthma in children.

Invited review. Knut Øymar K and Thomas Halvorsen.

Scand J Trauma Resusc Emerg Med., 2009 Sep 4;17(1):40.

14. Audiovisual assessment of exercise-induced laryngeal obstruction: reliability and validity of observations. Maat RC, Røksund O, Halvorsen T, Skadberg BT, Olofsson J, Ellingsen TA, Aarstad HJ, and Heimdal JH.

Eur Arch Otorhinolaryngol. 2009 Dec;266(12):1929-36.


15. Exercise induced dyspnea in the young. Larynx as the bottleneck of the airways.

Røksund OD, Maat RC, Heimdal JH, Olofsson J, Skadberg BT, and Halvorsen T.

Respiratory Medicine, 2009 Dec;103(12):1911-8. Epub 2009 Sep 26.


16. Health related quality of life after extremely preterm birth: a matched controlled cohort study. Vederhus BJ, Markestad T, Eide GE, Graue M, and Halvorsen T. Health Quality of Life Outcomes, 2010 May 23;8:53.

17. Left vocal cord paralysis after extreme preterm birth, a new clinical scenario in adults. Røksund O, Clemm H, Heimdal JH, Aukland SM, Sandvik L, Markestad T, and Halvorsen T.
Pediatrics, 2010 Dec; 126(6):e1569-77.


18. Use of post-exercise laryngoscopy to evaluate exercise induced dyspnea  

Halvorsen T, Røksund OD, Maat RC, and Heimdal JH.

Pediatric Pulmonology, 2011 Feb 17.                              

19. Exercise-induced laryngeal obstruction: natural history and effect of surgical treatment. Maat RC, Hilland M, Røksund OD, Halvorsen T, Olofsson J, Aarstad HJ, Heimdal H.
Eur Arch Otorhinolaryngol. 2011 Oct;268(10):1485-92.

20. Larynx in exercising humans; the unexplored bottleneck of the airways

Halvorsen T, Røksund O, Olofsson J, and Heimdal JH.

Pediatrics, December 2011;128 (6).                                

21. Exercise induced laryngeal obstruction (EILO): Diagnosis and Management.

Heimdal JH, Halvorsen T, Maat RC, Røksund OD and Olofsson J
ENT Masterclass 2011; 4 (1); 117-123. 


22. Aerobic capacity and exercise performance in young people born extremely preterm.

Clemm H, Røksund O, Thorsen E, Eide GE, Markestad T, and Halvorsen T.

Pediatrics, January 2012;129(1):e97-105.

23. The outcome after severe bronchiolitis is related to gender and virus. Mikalsen IB, Halvorsen T,
and Øymar K. Pediatric Allergy Immunology, June 2012; 23(4):391-8.

24. Pain tolerance and pain perception in adolescents born extremely preterm.

Vederhus BJ, Eide GE, Natvig GK, Markestad M, Graue M, and Halvorsen T.

Journal of Pain, October 2012; 13(10):978-8.


25. Severe bronchiolitis in infancy: Can asthma in adolescence be predicted?

Mikalsen IB, Halvorsen T, Eide GE, Øymar K.

Pediatr Pulmonol. 2013 Jun;48(6):538-44

26. Laryngeal movements during inspiratory muscle training in healthy subjects.

Sandnes A, Andersen T, Hilland M, Halvorsen T, Heimdal JH, Røksund OD.

J. Voice. 2013 Jul; 27(4):448-53

27. Lung function after preterm birth; development from mid-childhood to adulthood.

Vollsæter M, Røksund OD, Eide GE, Markestad M and Halvorsen T.

Thorax. 2013 Aug;68(8):767-76.

28. The optimal management of patients. Mikalsen IB, Halvorsen T, Oymar K.

Pediatric Pulmonology 2013 Sept; 48 (9):936

29. Laryngeal Response Patterns to Mechanical Insufflation-Exsufflation in Healthy Subjects. Andersen T, Sandnes A, Hilland M, Halvorsen T, Fondenes O, Heimdal JH, Tysnes OB, Røksund OD.
Am J Phys Med Rehabil. 2013 Oct;92(10):920-9.

30. Increased inflammatory markers in adolescents born extremely preterm and small for gestational age. Bjørke-Monsen A-L, Halvorsen T, Midttun Ø, Ueland PM.

Journal of Pediatric Biochemistry; Volume 3, Number 4, 2013


31. Exhaled nitric oxide is related to atopy, but not asthma in adolescents with previous bronchiolitis in infancy and controls. Mikalsen IB, Halvorsen T, Øymar K.

BMC Pulm Med. 2013 Nov 17;13:66.

32. Pulmonary gas transfer in children and adolescents born extremely preterm.

Satrell E, Røksund OD, Thorsen E, and Halvorsen T.

European Respiratory Journal. 2013 Dec; 42(6):1536-44.


33. Blood eosinophil counts during bronchiolitis are related to bronchial hyper-responsiveness and lung function in early adolescence. Mikalsen IB, Halvorsen T, Øymar K.  Acta Paediatrica 2014 Jan;103(1):86-92.

34. Exercise capacity after extremely preterm birth: development from adolescence to adulthood. Clemm HH, Vollsæter M, Røksund OD, Eide GE, Markestad T, Halvorsen T.
Annals American Thorac Society. 2014 May;11(4):537-45


35. Health-related quality of life and behavior after extreme preterm birth: development trajectories. Vederhus BJ, Eide GE, Natvig GK, Markestad T, Graue M, Halvorsen T.

PeerJ. 2015 Jan 20;3, pp:1-18; doi: 10.7717/peerj.738

36. Children Born Preterm at the Turn of the Millennium Had Better Lung Function Than Children Born Similarly Preterm in the Early 1990s. Vollsæter M, Skromme K, Satrell E, Clemm H, Røksund O, Øymar K, Markestad T, Halvorsen T. PLoS One. 2015 Dec 7;10 (12; pp:1-17.

37. Adult respiratory outcome of extreme preterm birth - a regional cohort study

Vollsæter M, Clemm HH, Satrell E, Røksund O, Markestad T, Halvorsen T.

Annals American Thorac Society. 2015 Mar;12(3):313-22.

38. Larynx during exercise; the unexplored bottleneck of the airways

Røksund OD, Heimdal JH, Olofsson J, Maat RC, Halvorsen T.   

Eur Arch Otorhinolaryngol. 2015 Sep; 272 (9):2101-9.

39. Health-related quality of life may deteriorate from adolescence to young adulthood after extremely preterm birth. Båtsvik B, Vederhus BJ, Halvorsen T, Wentzel-Larsen T, Graue M, Markestad T.
Acta Paediatr. 2015 Sep; 104 (9):948-55.

40. ERS/ELS/ACCP 2013 international consensus conference nomenclature on inducible laryngeal obstructions. Christensen PM, Heimdal JH, Christopher KL, Bucca C, Cantarella G, Friedrich G, Halvorsen T, Herth F, Jung H, Morris MJ, Remacle M, Rasmussen N, Wilson JA; ERS/ELS/ACCP Task Force on Inducible Laryngeal Obstructions. European Respiratory Review. 2015 Sep;24 (137):445-50. Review.

41. Respiratory illness contributed significantly to morbidity in children born extremely premature or with extremely low birth weights in 1999-2000. Skromme K, Leversen K, Eide GE, Markestad T, Halvorsen T. Acta Paediatr. 2015 Nov; 104 (11):1189-98.

42. A new non-invasive method of infant spirometry demonstrates a level of repeatability that is comparable to traditional methods. Bentsen MH, Haaland A, Lønning LB, Gudmundsdottir H, Markestad T, Halvorsen T. Acta Paediatr. 2015 Nov; 104 (11):1130-7.

43. Adolescents who were born extremely preterm demonstrate modest decreases in exercise capacity. Clemm HH, Vollsaeter M, Røksund OD, Markestad T, Halvorsen T.
Acta Paediatr. 2015 Nov; 104 (11):1174-81.



44. Comparison between two assessment methods for exercise-induced laryngeal obstructions.
Norlander K, Christensen PM, Maat RC, Halvorsen T, Heimdal JH, Morén S, Rasmussen N, Nordang L.
Eur Arch Otorhinolaryngol. 2016 Feb; 273 (2):425-30.

45. Respiratory Rate During the First 24 Hours of Lifein Healthy Term Infants.

Tveiten L, Diep LM, Halvorsen T, Markestad T

Pediatrics. 2016 Apr;137(4). pii: e20152326.

46. Congenital Laryngomalacia is related to Exercise Induced Laryngeal Obstruction in Adolescence.
Magnus Hilland , Ola Drange Røksund, Lorentz Sandvik, Øystein Haaland, Hans Jørgen Aarstad,
Thomas Halvorsen, John-Helge Heimdal MD
Arch Dis Child.; 2016 May;101(5):443-8. doi: 10.1136/archdischild-2015-308450

47. Electromagnetic inductance plethysmography is well suited to measure tidal breathing in infants.
Bentsen MHL, Eriksen M, Olsen MS, Markestad T, Halvorsen T.

ERJ Open Res. 2016 Nov 24;2(4). pii: 00062-2016.


48. Increased bronchial hyperresponsiveness and higher ADMA levels after fetal growth restriction.
Bjørke-Monsen AL, Vollsæter M, Ueland PM, Markestad T, Øymar K, Halvorsen T.
Am J Respir Cell Mol Biol. 2017 Jan;56(1):83-89

49. Exercise inducible laryngeal obstruction: diagnostics and management.
Røksund OD, Heimdal JH, Clemm H, Vollsæter M, Halvorsen T.
Paediatr Respir Rev. 2016 Jul 18. pii: S1526-0542(16)30063-X.

50. Ventilatory Efficiency in Children and Adolescents Born Extremely Preterm.
Hestnes J, Hoel H, Risa OJ, Romstøl HO, Røksund O, Frisk B, Thorsen E, Halvorsen T, Clemm HH.
Front Physiol. 2017 Jul 13;8:499.

51. Laryngeal response patterns influence the efficacy of mechanical assisted cough in amyotrophic lateral sclerosis. Andersen T, Sandnes A, Brekka AK, Hilland M, Clemm H, Fondenes O, Tysnes OB, Heimdal JH, Halvorsen T, Vollsæter M, Røksund OD.

Thorax. 2016 May 12. pii: thoraxjnl-2015-207555.

52. Systemiske steroider til førskolebarn med symptomer fra nedre luftveier. Øymar K, Mikalsen IB,
Nag T, Halvorsen T, Crowley S. Tidsskr Nor Laegeforen. 2017 May 23;137(10):698-699

53. Bronchial hyper-responsiveness after preterm birth.
Clemm HH, Engeseth M, Vollsæter M, Kotecha S, Halvorsen T.
Paediatr Respir Rev. 2017 Jun 20. pii: S1526-0542(17)30066-0.

54. Mid-childhood outcomes after pre-viable preterm premature rupture of membranes.

Bentsen MH, Satrell E, Reigstad H, Johnsen SL, Vollsæter M, Røksund OD, Greve G, Berg A,
Markestad T, Halvorsen T. J Perinatol. 2017 Jun 29.

55. Inducible laryngeal obstruction: an official joint European Respiratory Society and European Laryngological Society statement. Halvorsen T, Walsted ES, Bucca C, Bush A, Cantarella G, Friedrich G, Herth FJF, Hull JH, Jung H, Maat R, Nordang L, Remacle M, Rasmussen N, Wilson JA, Heimdal JH.
The European Respiratory Journal. 2017; 50(3).

56. Lung function at term in extremely preterm-born infants: a regional prospective cohort study. Bentsen MH, Markestad T, Øymar K, Halvorsen T.
BMJ open. 2017; 7(10):e016868; PMID: 29074512

57. Left vocal cord paralysis after patent ductus arteriosus ligation: A systematic review.
Engeseth MS, Olsen NR, Maeland S, Halvorsen T, Goode A, Røksund OD.
Paediatr Respir Rev. 2017 Nov 15. Review. PMID: 29336933



PRIVATE: Born 24.04.1959; married Line Omland (dentist, self employed); two sons in their 20s.

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