Clare Bradley, Rosalind Plowright, John Stewart, John Valentine and Elke Witthaus (2007) The Diabetes Treatment Satisfaction Questionnaire change version (DTSQc) evaluated in insulin glargine trials shows greater responsiveness to improvements than the original DTSQ.. Health and Quality of Life, 5 (1).
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The results of using status measures to identify any changes in treatment satisfaction strongly suggest a need for specific change instruments designed to overcome the ceiling effects frequently observed at baseline. Status measures may leave little room to show improvement in situations where baseline ceiling effects are observed. A change version of the DTSQ (DTSQc) is compared here with the original status (now called DTSQs) version to test the instruments' comparative ability to demonstrate change. Methods Two multinational, openlabel, randomised-controlled trials (one for patients with type 1 diabetes, the other for type 2) compared new, longer-acting insulin glargine with standard NPH basal insulin. The DTSQs was completed at baseline and the DTSQs and DTSQc at final visit by 351 English- and German-speaking patients. DTSQc scores were compared with change from baseline for the DTSQs, using 3-way analysis of variance, to examine Questionnaire, Treatment and Ceiling effects (i.e. baseline scores at/near ceiling). Results and discussion Significant Questionnaire effects and a Questionnaire × Ceiling interaction (p < 0.001) in both trial datasets showed that the DTSQc detected more improvement in Treatment Satisfaction than the DTSQs, especially when patients had DTSQs scores at/near ceiling at baseline. Additionally, significant Treatment effects favouring insulin glargine (p < 0.001) and a Treatment × Questionnaire interaction (p < 0.019), with the DTSQc showing more benefits, were found in the type 1 trial. Results for Perceived Hyper- and Hypoglycaemia also demonstrated important differences between the questionnaires in the detection of treatment effects. Tests of effect sizes showed these differences in response to change to be significantly in favour of the DTSQc. Conclusion The DTSQc, used in conjunction with the DTSQs, overcomes the problem of ceiling effects encountered when only the status measure is used and provides a means for new treatments to show greater value than is possible with the DTSQs alone.
This is a Published version This version's date is: 10/10/2007 This item is peer reviewed
https://repository.royalholloway.ac.uk/items/0dede910-6539-26a6-8ace-b16ad5a2d40c/1/
Deposited by () on 23-Dec-2009 in Royal Holloway Research Online.Last modified on 12-May-2010
Bradley C: Psychological issues in clinical trial design. The Irish J of Psychol 1997, 18:67-87. Petterson T, Lee P, Hollis S, Young B, Newton P, Dornan T: Well-being and treatment satisfaction in older people with diabetes. Diabetes Care 1998, 21:930-935. Wredling R, Ståhlhammer J, Adamson U, Berne C, Larsson Y, Östman J: Well-being and treatment satisfaction in adults with diabetes: a Swedish population-based study. Qual Life Res 1995, 4:515-522. Barnett AH, Bowen Jones D, Burden AC, Janes JM, Sinclair A, Small M, Tindall H: Multicentre study to assess quality of life and glycaemic control of type 2 diabetic patients treated with insulin compared with oral hypoglycaemic agents. Pract Diabetes Int 1996, 13:179-183. Bradley C: The Diabetes Treatment Satisfaction Questionnaire: DTSQ. In Handbook of Psychology and Diabetes: a guide to psychological measurement in diabetes research and practice. Edited by: Bradley C. Chur, Switzerland: Harwood Academic Publishers; 1994:111-132. Fitzpatrick R: Scope and measurement of patient satisfaction. In Measurement of patients' satisfaction with their care. Edited by: Fitzpatrick R, Hopkins A. London: Royal College of Physicians; 1993:1-17. Snoek FJ, Heine RJ: Ceiling effect reduces the validity of the Diabetes Treatment Satisfaction Questionnaire. Diabetes Care 1998, 21(11):2039-2039. Bradley C: Diabetes Treatment Satisfaction Questionnaire: Change version for use alongside status version provides appropriate solution where ceiling effects occur. Diabetes Care 1999, 22:530-532. Yki-Järvinen H, Dressler A, Ziemen M, the HOE901/3002 study group: Less nocturnal hypoglycaemia and better post-dinner glucose control with bedtime insulin glargine compared with bedtime NPH insulin during insulin combination therapy in type 2 diabetes. Diabetes Care 2000, 23:1130-1136. Witthaus E, Stewart J, Bradley C: Treatment satisfaction and psychological well-being with insulin glargine compared with NPH in patients with type 1 diabetes. Diabetic Medicine 2001, 18:619-625. Witthaus E, Stewart J, Bradley C: Psychological outcomes after initiation of insulin treatment in patients with type II diabetes [Abstract]. Diabetologia 2000, 43(S1):A205-787. Krans HMJ, Porta M, Keen H, Staehr Johansen K, Eds: Diabetes care and research in Europe: the St Vincent Declaration action programme. Implementation document. Copenhagen: WHO, Regional Office for Europe; 1995:40-47. Greenhalgh J: (The Role of) User Outcomes within Diabetes Care. Outcomes Briefing 1996, 8:10-16. Ishii H, Bradley C, Riazi A, Barendse S, Yamamoto T: The Japanese Version of the Diabetes Treatment Satisfaction Questionnaire (DTSQ): translation and clinical evaluation. Journal of Clinical and Experimental Medicine 2000, 192:809-814. Plowright R, Witthaus E, Bradley C: Psychometric evaluation of Diabetes Treatment Satisfaction Questionnaire in 8 languages [Abstract]. Proc Br Psychol Soc 2000, 8(2):43. Bradley C, Lewis KS: Measures of psychological well-being and treatment satisfaction developed from the responses of people with tablet-treated diabetes. Diabetic Medicine 1990, 7:445-451. Howorka K, Pumprla J, Schlusche C, Wagner-Nosiska D, Schabmann A, Bradley C: Dealing with ceiling baseline treatment satisfaction level in patients with diabetes under flexible, functional insulin treatment: assessment of improvements in treatment satisfaction with a new insulin analogue. Qual Life Res 2000, 9:915-930. Bradley C, Todd C, Gorton T, Symonds E, Martin A, Plowright R: The development of an individualised questionnaire measure of perceived impact of diabetes on quality of life: the ADDQoL. Qual Life Res 1999, 8:79-91. Clark-Carter D: Doing Quantitative Psychological Research: From Design to Report. Volume 193. Hove, UK: Psychology Press; 1997:550-62. Ratner RE, Hirsch IB, Neifing JL, Garg SK, Mecca TE, Wilson CA: Less hypoglycaemia with insulin glargine in intensive insulin therapy for type 1 diabetes. US Study Group of Insulin Glargine in Type 1 Diabetes. Diabetes Care 2000, 23:639-643. Pieber TR, Eugène-Jolchine I, Derobert E, the European Study Group: Efficacy and safety of HOE 901 versus NPH Insulin in patients with type 1 diabetes. Diabetes Care 2000, 23:157-162. Aseltine RH Jr, Carlson KJ, Fowler FJ, Barry MJ: Comparing prospective and retrospective measures of treatment outcomes. Med Care 1995, 33:AS67-AS76. The DAFNE Study Group: Training in flexible, intensive insulin management to enable dietary freedom in people with type 1 diabetes: dose adjustment for normal eating (DAFNE) randomised controlled trial. BMJ 2002, 325:746-749.