Clinical effectiveness and cost-effectiveness of foam sclerotherapy, endovenous laser ablation and surgery for varicose veins: Results from the comparison of LAser, Surgery and foam Sclerotherapy (CLASS) randomised controlled trial

Health Technology Assessment

Volumn 19, Issue 27, 2015, Pages 1-341

  Brittenden, Julie ^a   Cotton, Seonaidh C ^b   Elders, Andrew ^b   Tassie, Emma ^a   Scotland, Graham ^a,b   Ramsay, Craig R ^b   Norrie, John ^b   Burr, Jennifer ^c   Francis, Jill ^d   Wileman, Samantha ^b   Campbell, Bruce ^e   Bachoo, Paul ^a   Chetter, Ian ^f   Gough, Michael ^g   Earnshaw, Jonothan ^h   Lees, Tim ⁱ   Scott, Julian ^g   Baker, Sara A ^j   MacLennan, Graeme ^b   Prior, Maria ^b   Bolsover, Denise ^b   Campbell, Marion K ^b   more..

^a UNIVERSITY OF ABERDEEN   (United Kingdom)

^b UNIVERSITY OF ABERDEEN   (United Kingdom)

^c UNIVERSITY OF ST ANDREWS   (United Kingdom)

^d CITY UNIVERSITY   (United Kingdom)

^e ROYAL DEVON AND EXETER HOSPITAL   (United Kingdom)

^f HULL ROYAL INFIRMARY   (United Kingdom)

^g ST JAMES S UNIVERSITY HOSPITAL   (United Kingdom)

^h GLOUCESTERSHIRE ROYAL HOSPITAL   (United Kingdom)

ⁱ FREEMAN HOSPITAL   (United Kingdom)

^j ROYAL BOURNEMOUTH HOSPITAL   (United Kingdom)

more..

Author keywords

[No Author keywords available]

Indexed keywords

ABERDEEN VARICOSE VEIN QUESTIONNAIRE; ARTICLE; CLINICAL EFFECTIVENESS; COST EFFECTIVENESS ANALYSIS; DISEASE ASSESSMENT; ENDOVASCULAR LASER ABLATION; EUROPEAN QUALITY OF LIFE 5 DIMENSIONS; FOAM SCLEROTHERAPY; HEADACHE; HEALTH CARE COST; HUMAN; LASER SURGERY; MULTICENTER STUDY (TOPIC); PARESTHESIA; POSTOPERATIVE COMPLICATION; QUALITY ADJUSTED LIFE YEAR; QUALITY OF LIFE ASSESSMENT; RANDOMIZED CONTROLLED TRIAL (TOPIC); SAPHENOUS VEIN; SCLEROTHERAPY; SHORT FORM 36; SKIN BRUISING; UNITED KINGDOM; VARICOSIS; VEIN SURGERY; VENOUS CLINICAL SEVERITY SCORE; ADOLESCENT; ADULT; ADVERSE EFFECTS; AGED; BIOMEDICAL TECHNOLOGY ASSESSMENT; CLINICAL TRIAL; CONTROLLED STUDY; COST BENEFIT ANALYSIS; DAILY LIFE ACTIVITY; ECONOMICS; FEMALE; LOW LEVEL LASER THERAPY; MALE; MIDDLE AGED; MULTICENTER STUDY; NATIONAL HEALTH SERVICE; PROCEDURES; RANDOMIZED CONTROLLED TRIAL; RECURRENT DISEASE; SEVERITY OF ILLNESS INDEX; STATISTICS AND NUMERICAL DATA; TREATMENT OUTCOME; VARICOSE VEINS; VERY ELDERLY; YOUNG ADULT;

ACTIVITIES OF DAILY LIVING; ADOLESCENT; ADULT; AGED; AGED, 80 AND OVER; COST-BENEFIT ANALYSIS; FEMALE; GREAT BRITAIN; HEALTH EXPENDITURES; HUMANS; LASER THERAPY; MALE; MIDDLE AGED; OUTCOME AND PROCESS ASSESSMENT (HEALTH CARE); QUALITY-ADJUSTED LIFE YEARS; RECURRENCE; SCLEROTHERAPY; SEVERITY OF ILLNESS INDEX; STATE MEDICINE; TECHNOLOGY ASSESSMENT, BIOMEDICAL; VARICOSE VEINS; YOUNG ADULT;

EID: 84929463628     PISSN: 13665278     EISSN: 20464924     Source Type: Journal    
DOI: 10.3310/hta19270     Document Type: Article

References (107)

1. Ladropoulos N, Leaon M, Nicolaides AN, Giannoukas AD, Volteas N, Chan P. Superficial venous insufficiency: correlation with anatomical extent of reflux with clinical symptoms and signs. J Vasc Surg 1994;20:953–8. http://dx.doi.org/10.1016/0741-5214(94)90233-X
2. Health and Social Care Information Centre. Hospital Episode Statistics. URL: www.hesonline.nhs. uk/Ease/servlet/ContentServer?site=1937&categoryID=192 (accessed 23 August 2013).
3. van Rij AM, Jiang P, Solomon C, Christie RA, Hill GB. Recurrence after varicose vein surgery: A prospective long-term clinical study with duplex ultrasound scanning. J Vasc Surg 2003;38:935–43. http://dx.doi.org/10.1016/S0741-5214(03)00601-3
4. Beale RJ, Gough MJ. Treatment options for primary varicose veins – a review. Eur J Vasc Endovasc Surg 2005;30:83–95. http://dx.doi.org/10.1016/j.ejvs.2005.02.023
5. Bradbury A, Evans CJ, Allan P, Lee AJ, Ruckley CV, Fowkes FG. The relationship between lower limb symptoms and superficial and deep venous reflux on duplex ultrasonography: The Edinburgh Vein Study. J Vasc Surg 2000;32:921–31. http://dx.doi.org/10.1067/mva.2000.110509
6. Subramonia S, Lees T. Sensory abnormalities and bruising after long saphenous vein stripping: impact on short-term quality of life. J Vasc Surg 2005;42:510–14. http://dx.doi.org/10.1016/j.jvs.2005.05.021
7. Mackenzie RK, Lee AJ, Paisley A, Burns P, Allan PL, Ruckley CV, et al. Patient, operative and surgeon factors that influence the effect of superficial venous surgery on disease-specific quality of life. J Vasc Surg 2002;36:896–902. http://dx.doi.org/10.1067/mva.2002.128638
8. Mackenzie RK, Paisley A, Allan PL, Lee AJ, Ruckley CV, Bradbury AW. The effect of long saphenous stripping on quality of life. J Vasc Surg 2002;35:1197–203. http://dx.doi.org/10.1067/mva.2002.121985
9. Smith JJ, Garratt AM, Guest M, Greenhalgh RM, Davies AH. Evaluating and improving health-related quality of life in patients with varicose veins. J Vasc Surg 1999;30:710–19. http://dx.doi.org/10.1016/S0741-5214(99)70110-2
10. Ratcliffe J, Brazier JE, Campbell WB, Palfreyman S, MacIntyre JB, Michaels JA. Cost-effectiveness analysis of surgery versus conservative treatment for uncomplicated varicose veins in a randomised clinical trial. Br J Surg 2006;93:182–6. http://dx.doi.org/10.1002/bjs.5263
11. National Institute for Health and Care Excellence (NICE). Endovenous Laser Treatment of the Long Saphenous Vein. NICE Interventional Procedure Guidance 52. London: NICE; 2004.
12. National Institute for Health and Care Excellence (NICE). Radiofrequency Ablation of Varicose Veins. NICE Interventional Procedure Guidance 8. London: NICE; 2003.
13. National Institute for Health and Care Excellence (NICE). Ultrasound-guided Foam Sclerotherapy for Varicose Veins. NICE Interventional Procedure Guidance 182. London: NICE; 2006.
14. Wright D, Gobin JP, Bradbury A, Coleridge-Smith P, Spoelstra H, Berridge D, et al. Varisolve polidocanol microfoam compared with surgery or sclerotherapy in the management of varicose veins in the presence of trunk vein incompetence: European randomised controlled trial. Phlebology 2006;21:180–90. http://dx.doi.org/10.1258/026835506779115807
15. Darwood RJ, Theivacumar N, Dellagrammaticas D, Mavor AI, Gough MJ. Randomized clinical trial comparing endovenous laser ablation with surgery for the treatment of primary great saphenous varicose veins. Br J Surg 2008;95:294–301. http://dx.doi.org/10.1002/bjs.6101
16. Winterborn RJ, Corbett CR. Treatment of varicose veins: the present and the future – a questionnaire survey. Ann R Coll Surg Engl 2008;90:561–4. http://dx.doi.org/10.1308/003588408X318228
17. Guex JJ. Foam sclerotherapy: an overview of use for primary venous insufficiency. Sem Vasc Surg 2005;18:25–9. http://dx.doi.org/10.1053/j.semvascsurg.2004.12.008
18. Jia X, Mowatt G, Burr JM, Cook JA, Fraser C. Systematic review of the safety and efficacy of foam sclerotherapy for venous disease of the lower limbs. Br J Surg 2007;94:925–36. http://dx.doi.org/10.1002/bjs.5891
19. Cabrera J, Cabrera JJ, Garcia-Olmedo MA. Treatment of varicose long saphenous veins with sclerosant in microfoam form: long-term outcomes. Phlebology 2000;15:19–23. http://dx.doi.org/10.1007/s005230070032
20. Smith PC. Chronic venous disease treated by ultrasound guided foam sclerotherapy. Eur J Vasc Endovasc Surg 2006;32:577–83. http://dx.doi.org/10.1016/j.ejvs.2006.04.033
21. Breu FX, Guggenbichler S. European consensus meeting on foam sclerotherapy, April 4–6, 2003, Tegernsee, Germany. Dermatol Surg 2004;30:709–17. http://dx.doi.org/10.1111/j.1524-4725.2004.30209.x
22. Beale RJ, Mavor AID, Gough MJ. Minimally invasive treatment for varicose veins: a review of endovenous laser treatment and radiofrequency ablation. Int J Low Extrem Wounds 2004;3:188–97. http://dx.doi.org/10.1177/1534734604272245
23. Proebstle TM, Sandhofer M, Kargl A, Gul D, Rother W, Knop J, et al. Thermal damage of the inner vein wall during endovenous laser treatment; key role of energy absorption by intravascular blood. Dermatol Surg 2002;28:596–600.
24. Bush RG, Shamma HN, Hammond KA. 940-nm laser for treatment of saphenous insufficiency: histological analysis and long-term follow-up. Photomed Laser Surg 2005;23:15–19. http://dx.doi.org/10.1089/pho.2005.23.15
25. Timpermann PE, Sichlau M, Ryu R. Greater energy delivery improves treatment success of endovenous laser treatment of incompetent saphenous veins. J Vasc Interv Radiol 2004;15:1061–3. http://dx.doi.org/10.1097/01.RVI.0000130382.62141.AE
26. Mundy L, Merlin TL, Fitridge RA, Hiller JE. Systematic review of endovenous laser treatment for varicose veins. Br J Surg 2005;92:1189–94. http://dx.doi.org/10.1002/bjs.5142
27. Medical Services Advisory Committee. Endovenous Laser Treatment for Varicose Veins. MSAC; 2003. URL: www.msac.gov.au/internet/msac/publishing.nsf/Content/CA1C4AC50025A411CA25 75AD0082FDCA/$File/1059-Assessment-Report.pdf (accessed 1 August 2006).
28. National Institute for Health and Care Excellence (NICE). Varicose Veins in the Legs. CG168. NICE; 2013. URL: http://guidance.nice.org.uk/CG168 (accessed 27 August 2013).
29. Rasmussen LH, Lawaetz M, Bjoern L, Vennits B, Blemings A, Eklof B. Randomised clinical trial comparing endovenous laser ablation, radiofrequency ablation, foam sclerotherapy and surgical stripping for great saphenous varicose veins. Br J Surg 2011;98:1079–87. http://dx.doi.org/10.1002/bjs.7555
30. Figueiredo M, Araujo S, Barros NJ, Miranda FJ. Results of surgical treatment compared with ultrasound-guided foam sclerotherapy in patients with varicose veins: a prospective randomised study. Eur J Vasc Endovasc Surg 2009;38:758–63. http://dx.doi.org/10.1016/j.ejvs.2009.07.015
31. Biemans AAM, Kockaert M, Akkersdijk GP, van den Bos RR, De Maeseneer MGR, Cuypers P, et al. Comparing endovenous laser ablation, foam sclerotherapy, and conventional surgery for great saphenous varicose veins. J Vasc Surg 2013;58:727–34. http://dx.doi.org/10.1016/j.jvs.2012.12.074
32. Lattimer CR, Azzam M, Kalodiki E, Shawish E, Trueman P, Geroulakos G. Cost and effectiveness of laser with phlebectomies compared with foam sclerotherapy in superficial venous insufficiency. Early results of a randomised controlled trial. Eur J Vasc Endovasc Surg 2012;43:594–600. http://dx.doi.org/10.1016/j.ejvs.2012.01.032
33. Shadid N, Ceulen R, Nelemans P, Dirksen C, Veraart J, Schurink GW, et al. Randomized clinical trial of ultrasound-guided foam sclerotherapy versus surgery for the incompetent great saphenous vein. Br J Surg 2012;99:1062–70. http://dx.doi.org/10.1002/bjs.8781
34. Christenson JT, Gueddi S, Gemayel G, Bounameaux H. Prospective randomised trial comparing endovenous laser ablation and surgery for treatment of primary great saphenous varicose veins with a 2-year follow-up. J Vasc Surg 2010;52:1234–41. http://dx.doi.org/10.1016/j.jvs.2010.06.104
35. Carradice D, Mekako AI, Mazari FA, Samuel N, Hatfield J, Chetter IC. Clinical and technical outcomes from a randomised clinical trial of endovenous laser ablation compared with conventional surgery for great saphenous varicose veins. Br J Surg 2011;98:1117–23. http://dx.doi.org/10.1002/bjs.7615
36. Rasmussen LH, Bjoern L, Lawaetz M, Blemings A, Lawaetz B, Eklof B. Randomised trial comparing endovenous laser ablation of the great saphenous vein with high ligation and stripping in patients with varicose veins: short-term results. J Vasc Surg 2007;46:308–15. http://dx.doi.org/10.1016/j.jvs.2007.03.053
37. Samuel N, Carradice D, Wallace T, Mekako A, Hatfield J, Chetter I. Randomised clinical trial of endovenous laser therapy versus conventional surgery for short saphenous varicose veins. Ann Surg 2013;257:419–26. http://dx.doi.org/10.1097/SLA.0b013e318275f4e4
38. Rass K, Frings N, Glowacki P, Hamsch C, Graber S, Vogt T, et al. Comparable effectiveness of endovenous laser ablation and high ligation with stripping of the great saphenous vein: two-year results of a randomized clinical trial (RELACS study). Arch Dermatol 2012;148:49–58. http://dx.doi.org/10.1001/archdermatol.2011.272
39. Flessenkamper I, Hartmann M, Stenger D, Roll S. Endovenous laser ablation with and without high ligation compared with high ligation and stripping in the treatment of great saphenous varicose veins: initial results of a multicentre randomised controlled trial. Phlebology 2013;28:16–23.
40. Pronk P, Gauw SA, Mooij MC, Gaastra MT, Lawson JA, van Goethem AR, et al. Randomised controlled trial comparing sapheno-femoral ligation and stripping of the great saphenous vein with endovenous laser ablation (980 nm) using local tumescent anaesthesia: one year results. Eur J Vasc Endovasc Surg 2010;40:649–56. http://dx.doi.org/10.1016/j.ejvs.2010.08.007
41. Edwards AG, Baynham S, Lees T, Mitchell DC. Management of varicose veins: a survey of current practice by members of the Vascular Society of Great Britain and Ireland. Ann R Coll Surg Engl 2009;91:77–80. http://dx.doi.org/10.1308/003588409X358953
42. Shepherd AC, Gohel MS, Hamish M, Lim CS, Davies AH. Endovenous treatments for varicose veins – over-taking or over-rated? Phlebology 2010;25:38–43. http://dx.doi.org/10.1258/phleb.2009.008091
43. Kanwar A, Hansrani M, Lees T, Stansby G. Trends in varicose vein therapy in England: radical changes in the last decade. Ann R Coll Surg Engl 2010;92:341–6. http://dx.doi.org/10.1308/003588410X12518836440649
44. Health and Social Care Information Centre (HSCIC). PROMs Outcomes Summary by Provider, April 2010–March 2011. HSCIC; 2012. URL: www.hscic.gov.uk/catalogue/PUB07049/fina-prom-eng-apr-10-mar-11-pre-post-tab3.xls (accessed 23 August 2013).
45. Liu X, Jia X, Guo W, Xiong J, Zhang H, Liu M, et al. Ultrasound-guided foam sclerotherapy of the great saphenous vein with sapheno-femoral ligation compared to standard stripping: a prospective clinical study. Int Angiol 2011;30:321–6.
46. Abela R, Liamis A, Prionidis I, Mathai J, Gorton L, Browne T, et al. Reverse foam sclerotherapy of the great saphenous vein with sapheno-femoral ligation compared to standard and invagination stripping: a prospective clinical series. Eur J Vasc Endovasc Surg 2008;36:485–90. http://dx.doi.org/10.1016/j.ejvs.2008.06.029
47. Bountouroglou DG, Azzam M, Kakkos SK, Pathmarajah M, Young P, Geroulakos G. Ultrasound-guided foam sclerotherapy combined with sapheno-femoral ligation compared to surgical treatment of varicose veins: early results of a randomised controlled trial. Eur J Vasc Endovasc Surg 2006;31:93–100. http://dx.doi.org/10.1016/j.ejvs.2005.08.024
48. Kalodiki E, Azzam M, Lattimer CR, Shawish E, Zambas N, Geroulakos G. Randomised controlled trial of ultrasound guided foam sclerotherapy combined with sapheno-femoral ligation compared to surgical treatment of varicose veins: five-year results. J Vasc Surg 2011;53(Suppl. 19):259–60. http://dx.doi.org/10.1016/j.jvs.2010.11.025
49. Rasmussen LH, Bjoern L, Lawaetz M, Blemings A, Eklof B. Randomised clinical trial comparing endovenous laser ablation with stripping of the great saphenous vein: clinical outcome and recurrence after 2 years. Eur J Vasc Endovasc Surg 2010;39:630–5. http://dx.doi.org/10.1016/j.ejvs.2009.11.040
50. Carradice D, Mekako AI, Mazari FAK, Samuel N, Hatfield J, Chetter IC. Randomised clinical trial of endovenous laser ablation compared with conventional surgery for great saphenous varicose veins. Br J Surg 2011;98:501–10. http://dx.doi.org/10.1002/bjs.7394
51. Rasmussen LH, Lawaetz M, Bjoern L, Blemings A, Eklof B. Randomized clinical trial comparing endovenous laser ablation and stripping of the great saphenous vein with clinical and duplex outcome after 5 years. J Vasc Surg 2013;58:421–6. http://dx.doi.org/10.1016/j.jvs.2012.12.048
52. van den Bos R, Arends L, Kockaert M, Neumann M, Nijsten T. Endovenous therapies of lower extremity varicosities: a meta-analysis. J Vasc Surg 2009;49:230–9. http://dx.doi.org/10.1016/j.jvs.2008.06.030
53. Luebke T, Brunkwall J. Systematic review and meta-analysis of endovenous radiofrequency obliteration, endovenous laser therapy, and foam sclerotherapy for primary varicosis. J Cardiovasc Surg (Torino) 2008;49:213–33.
54. Gohel MS, Epstein DM, Davies AH. Cost-effectiveness of traditional and endovenous treatments for varicose veins. Br J Surg 2010;97:1815–23. http://dx.doi.org/10.1002/bjs.7256
55. Berridge D, Lees T, Earnshaw JJ. The VEnous INtervention (VEIN) Project. Phlebology 2009;24(Suppl. 1):1–2. http://dx.doi.org/10.1258/phleb.2009.09s001
56. Nesbitt C, Eifell RK, Coyne P, Badri H, Bhattacharya V, Stansby G. Endovenous ablation (radiofrequency and laser) and foam sclerotherapy versus conventional surgery for great saphenous vein varices (review). Cochrane Database Syst Rev 2011;10:CD005624.
57. Calvert M, Blazeby J, Altman DG, Revicki DA, Moher D, Brundage MD, et al. Reporting of patient-reported outcomes in randomized trials: the CONSORT PRO extension. JAMA 2013;309:814–22. http://dx.doi.org/10.1001/jama.2013.879
58. Michaels JA, Brazier JE, Campbell WB, Macintyre JB, Palfreyman SJ, Ratcliffe J. Randomized clinical trial comparing surgery with conservative treatment for uncomplicated varicose veins. Br J Surg 2006;93:175–81. http://dx.doi.org/10.1002/bjs.5264
59. Garratt AM, Macdonald LM, Ruta DA, Russell IT, Buckingham JK, Krukowski ZH. Towards measurement of outcome for patients with varicose veins. Qual Health Care 1993;2:5–10. http://dx.doi.org/10.1136/qshc.2.1.5
60. Garratt AM, Ruta DA, Abdalla MI, Russell IT. Responsiveness of the SF-36 and a condition-specific measure of health for patients with varicose veins. Qual Life Res 1996;5:223–34. http://dx.doi.org/10.1007/BF00434744
61. Ware JE. SF-36® Health Survey Update. URL: www.sf-36.org/tools/sf36.shtml (accessed 23 August 2013).
62. Kundu S, Lurie F, Millward SF, Padberg F, Vedantham S, Elias S, et al. Recommended reporting standards for endovenous ablation for the treatment of venous insufficiency: joint statement of the American Venous Forum and the Society of Interventional Radiology. J Vasc Surg 2007;46:582–9. http://dx.doi.org/10.1016/j.jvs.2007.05.025
63. Moss-Morris R, Weinman J, Petrie KJ, Horne R, Cameron LD, Buick D. The Revised Illness Perception Questionnaire (IPQ-R). Psychol Health 2002;17:1–16. http://dx.doi.org/10.1080/08870440290001494
64. Great Britain. Data Protection Act 1988. London: The Stationery Office; 1988.
65. Michaels JA, Campbell WB, Brazier JE, MacIntyre JB, Palfreyman SJ, Ratcliffe J, et al. Randomised clinical trial, observational study and assessment of cost-effectiveness of the treatment of varicose veins (REACTIV trial). Health Technol Assess 2006;10(13). http://dx.doi.org/10.3310/hta10130
66. White IR, Horton NJ, Carpenter J, Pocock SJ. Strategy for intention to treat analysis in randomised trials with missing outcome data. BMJ 2011;342:d40. http://dx.doi.org/10.1136/bmj.d40
67. Fairclough DL. Design and Analysis of Quality of Life Studies in Clinical Trials. Boca Raton, FL: CRC Press; 2002.
68. Leventhal H, Leventhal EA, Cameron L. Representations, Procedures and Effect in Illness Self-regulation: A Perceptual-Cognitive Model. In Baum A, Taylor SE, Singer JE, editors. Handbook of Health Psychology. Hillsdale, NJ: Lawrence Erlbaum; 2001. pp. 19–47.
69. Liu R, Skelly M, Weinman J. Effects of background stress and anxiety on postoperative recovery. Anaesthesia 1994;49:382–6. http://dx.doi.org/10.1111/j.1365-2044.1994.tb03467.x
70. Philips HC. Avoidance behaviour and its role in sustaining chronic pain. Behav Res Ther 1987;25:273–9. http://dx.doi.org/10.1016/0005-7967(87)90005-2
71. Fergusson D, Aaron SD, Guyatt G, Hebert P. Post-randomisation exclusions: the intention to treat principle and excluding patients from analysis. BMJ 2002;325:652–4. http://dx.doi.org/10.1136/bmj.325.7365.652
72. Kundu S, Lurie F, Millward SF, Padberg FTJ, Vedantham S, Elias SM, et al. Recommended reporting standards for endovenous ablation for the treatment of venous insufficiency: joint statement of the American Venous Forum and the Society of Interventional Radiology. J Vasc Interv Radiol 2009;20(Suppl. 7):417–24. http://dx.doi.org/10.1016/j.jvir.2009.04.019
73. Carradice D, Mekako AI, Hatfield J, Chetter IC. Randomised clinical trial of concomitant or sequential phlebectomy after endovenous laser therapy for varicose veins. Br J Surg 2009;96:369–75. http://dx.doi.org/10.1002/bjs.6556
74. World Health Organization (WHO). International Classification of Functioning, Disability and Health. WHO; 2001. URL: www.who.int/classifications/icf/en/ (accessed 23 August 2013).
75. Dixon D, Johnston M. Disability. In French DP, Kaptein AA, Vedhara K, Weinmann J, editors. Health Psychology. 2nd edn. Oxford: Wiley-Blackwell; 2010. pp. 317–28.
76. Francis JJ, Duncan EM, Prior ME, MacLennan G, Marshall AP, Wells EC, et al. Comparison of four methods for assessing the importance of attitudinal beliefs: an international Delphi study in intensive care settings. Br J Health Psychol 2014;19:274–91. http://dx.doi.org/10.1111/bjhp.12066
77. Royston P, Parmar MKB. Flexible proportional-hazards and proportional-odds models for censored survival data, with application to prognostic modelling and estimation of treatment effects. Stat Med 2002;21:2175–97. http://dx.doi.org/10.1002/sim.1203
78. StataCorp. Stata Multiple-Imputation Reference Manual Release 12. College Station, TX: StataCorp LP; 2012.
79. Royston P. Flexible alternatives to the Cox model, and more. Stata J 2001;1:1–28.
80. Ross MD. The relationship between functional levels and fear-avoidance beliefs following anterior cruciate ligament reconstruction. J Orthop Traumatol 2010;11:237–43. http://dx.doi.org/10.1007/s10195-010-0118-7
81. Lethem J, Slade PD, Troup JD, Bentley G. Outline of a Fear-Avoidance Model of exaggerated pain perception I. Behav Res Ther 1983;21:401–8. http://dx.doi.org/10.1016/0005-7967(83)90009-8
82. Dolan P, Gudex C, Kind P, Williams A. The time trade-off method: results from a general population study. Health Econ 1996;5:141–54. http://dx.doi.org/10.1002/(SICI)1099-1050(199603)5:2<141::AID-HEC189>3.0.CO;2-N
83. Brazier J, Roberts J, Deverill M. The estimation of a preference-based measure of health from the SF-36. J Health Econ 2002;21:271–92. http://dx.doi.org/10.1016/S0167-6296(01)00130-8
84. Glick H, Doshi J, Sonnad S, Polsky D. Economic Evaluation in Clinical Trials. New York, NY: Oxford University Press; 2007.
85. Joint Formulary Committee. British National Formulary. 63 ed. London: BMJ Group and Pharmaceutical Press; 2012.
86. Department of Health. NHS Reference Costs 2010–11. 2011. URL: www.gov.uk/government/ publications/2010-11-reference-costs-publication (accessed October 2012).
87. Curtis L. Unit Costs of Health and Social Care 2011. Canterbury: PSSRU, University of Kent; 2011. URL: www.pssru.ac.uk/pdf/uc/uc2011/uc2011.pdf (accessed October 2012).
88. ISD Scotland. ISD Scotland 63. URL: www.isdscotland.org/Health-Topics/Finance/Costbook/Speciality-Costs/Overhead.asp (accessed October 2012).
89. Department for Transport. Value of Time and Operating Costs: Transport Analysis Guidance (TAG). 2013. URL: www.dft.gov.uk/webtag/documents/archive/1208/unit3.5.6.pdf (accessed August 2013).
90. Office for National Statistics (ONS). 2011 Annual Survey of Hours and Earnings (SOC 2000). ONS; 2011. URL: www.ons.gov.uk/ons/dcp171778_241497.pdf (accessed December 2012).
91. NHS Pay Review Body. Twenty-sixth Report 2012. London: The Stationery Office; 2012. URL: www.official-documents.gov.uk/document/cm82/8298/8298.pdf (accessed December 2012).
92. Rubin DB. Multiple Imputation for Nonresponse in Surveys. New York, NY: J. Wiley & Sons; 1987. http://dx.doi.org/10.1002/9780470316696
93. Siribumrungwong B, Noorit P, Wilasrusmee C, Attia J, Thakkinstian A. A systematic review and meta-analysis of randomised controlled trials comparing endovenous ablation and surgical intervention in patients with varicose veins. Eur J Vasc Endovasc Surg 2012;44:214–23. http://dx.doi.org/10.1016/j.ejvs.2012.05.017
94. Perala J, Rautio T, Biancari F, Ohtonen P, Wiik H, Heikkinen T, et al. Radiofrequency endovenous obliteration versus stripping of the long saphenous vein in the management of primary varicose veins: 3-year outcome of a randomized study. Ann Vasc Surg 2005;19:669–72. http://dx.doi.org/10.1007/s10016-005-6613-2
95. Office for National Statistics (ONS). Interim Life Tables 2007–2009. URL: www.ons.gov.uk/ons/publications/re-reference-tables.html?edition=tcm%3A77-61850 (accessed 27 August 2013).
96. National Institute for Health and Care Excellence (NICE). Guide to the Methods of Technology Appraisal 2013. URL: www.nice.org.uk/article/chapter/1-introduction (accessed 15 June 2013).
97. Vasquez MA, Rabe E, McLafferty RB, Shortell CK, Marston WA, Gillespie D, et al. Revision of the venous clinical severity score: venous outcomes consensus statement: special communication of the American Venous Forum Ad Hoc Outcomes Working Group. J Vasc Surg 2010;52:1387–96. http://dx.doi.org/10.1016/j.jvs.2010.06.161
98. Bradbury AW, Adam DJ, Bell J, Forbes JF, Fowkes FG, Gillespie I, et al. Multicentre randomised controlled trial of the clinical and cost-effectiveness of a bypass-surgery-first versus a balloon-angioplasty-first revascularisation strategy for severe limb ischaemia due to infrainguinal disease. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial. Health Technol Assess 2010;14(14). http://dx.doi.org/10.3310/hta14140
99. Anon. Recruitment of women to clinical trials. Lancet 2001;358:853. http://dx.doi.org/10.1016/S0140-6736(01)06078-0
100. Benson JR. Recruitment of women into trials. Lancet 2002;359:164. http://dx.doi.org/10.1016/S0140-6736(02)07341-5
101. Thornton H, Dixon-Woods M. Recruitment of women into trials. Lancet 2002;359:164. http://dx.doi.org/10.1016/S0140-6736(02)07342-7
102. Smyth A, Hyman-Taylor P, Lewis S, Knox A, Stephenson T. Recruitment of women into trials. Lancet 2002;359:165–6. http://dx.doi.org/10.1016/S0140-6736(02)07344-0
103. Creel AH, Losinia E, Mandi LA, Marx RJ, Mahomed NN, Martin SD, et al. An assessment of willingness to participate in a randomised trial of arthroscopic knee surgery in patients with osteoarthritis. Contemp Clin Trials 2005;26:169–78. http://dx.doi.org/10.1016/j.cct.2004.12.010
104. Myles PS, Fletcher HE, Cairo S, Madder H, McRae R, Cooper J, et al. Randomised trial of informed consent and recruitment for clinical trials in the immediate preoperative period. Anaesthesiology 1999;91:969–78. http://dx.doi.org/10.1097/00000542-199910000-00016
105. National Institute for Health and Care Excellence (NICE). Referral Advice: A Guide to Appropriate Referral From General to Specialist Services: Varicose Veins. London: NICE; 2001.
106. Beresford T, Smith JJ, Brown L, Greenhalgh RM, Davies AH. A comparison of health-related quality of life of patients with primary and recurrent varicose veins. Phlebology 2003;18:35–7. http://dx.doi.org/10.1258/026835503321236885
107. Darvall KAL, Bate GR, Adam DJ, Bradbury AW. Recovery after ultrasound-guided foam sclerotherapy compared with conventional surgery for varicose veins. Br J Surg 2009;96:1262–7. http://dx.doi.org/10.1002/bjs.6754