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The Diabetes Treatment Satisfaction Questionnaire change version (DTSQc) evaluated in insulin glargine trials shows greater responsiveness to improvements than the original DTSQ.

Bradley C, Plowright R, Stewart J, Valentine J, Witthaus E - Health Qual Life Outcomes (2007)

Bottom Line: 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.Tests of effect sizes showed these differences in response to change to be significantly in favour of the DTSQc.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Health Psychology Research, Dept of Psychology, Royal Holloway, University of London, UK. c.bradley@rhul.ac.uk

ABSTRACT

Background: 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 x 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 x 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.

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Differential responsiveness of the DTSQ change and DTSQ status: perceived frequency of hypoglycaemia (Type 1 trial).
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Figure 2: Differential responsiveness of the DTSQ change and DTSQ status: perceived frequency of hypoglycaemia (Type 1 trial).

Mentions: Of the six sets of results (type 1 and type 2) for each of the three principal variables, change in Treatment Satisfaction (Tables 5 and 6), change in Perceived Hyperglycaemia (Tables 7 and 8) and change in Perceived Hypoglycaemia (Tables 9 and 10), the most relevant for comparison of the DTSQc with the DTSQs were those with skewed baseline distributions (Satisfaction and Perceived Hypoglycaemia) and attention is therefore focused primarily on these. Figures 1 and 2 provide two examples of the results, one for Treatment Satisfaction and one for Perceived Hypoglycaemia (both from the type 1 trial). For clarity of reading, all the ANOVA results, with both main effects and interactions, are presented in Tables 5, 7 and 9, and their related tables of means are given in Tables 6, 8 and 10 respectively. The text is restricted to the interpretation of these results.


The Diabetes Treatment Satisfaction Questionnaire change version (DTSQc) evaluated in insulin glargine trials shows greater responsiveness to improvements than the original DTSQ.

Bradley C, Plowright R, Stewart J, Valentine J, Witthaus E - Health Qual Life Outcomes (2007)

Differential responsiveness of the DTSQ change and DTSQ status: perceived frequency of hypoglycaemia (Type 1 trial).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2170436&req=5

Figure 2: Differential responsiveness of the DTSQ change and DTSQ status: perceived frequency of hypoglycaemia (Type 1 trial).
Mentions: Of the six sets of results (type 1 and type 2) for each of the three principal variables, change in Treatment Satisfaction (Tables 5 and 6), change in Perceived Hyperglycaemia (Tables 7 and 8) and change in Perceived Hypoglycaemia (Tables 9 and 10), the most relevant for comparison of the DTSQc with the DTSQs were those with skewed baseline distributions (Satisfaction and Perceived Hypoglycaemia) and attention is therefore focused primarily on these. Figures 1 and 2 provide two examples of the results, one for Treatment Satisfaction and one for Perceived Hypoglycaemia (both from the type 1 trial). For clarity of reading, all the ANOVA results, with both main effects and interactions, are presented in Tables 5, 7 and 9, and their related tables of means are given in Tables 6, 8 and 10 respectively. The text is restricted to the interpretation of these results.

Bottom Line: 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.Tests of effect sizes showed these differences in response to change to be significantly in favour of the DTSQc.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: Health Psychology Research, Dept of Psychology, Royal Holloway, University of London, UK. c.bradley@rhul.ac.uk

ABSTRACT

Background: 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 x 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 x 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.

Show MeSH
Related in: MedlinePlus