Psychometric validation of the Self-Care Inventory-Revised (SCI-R) in UK adults with type 2 diabetes using data from the AT.LANTUS Follow-on study

Leena Khagram, Colin R Martin, Melanie J Davies, Jane Speight, Leena Khagram, Colin R Martin, Melanie J Davies, Jane Speight

Abstract

Background: Achieving optimal outcomes in type 2 diabetes (T2DM) involves several demanding self-care behaviours, e.g. managing diet, activity, medications, monitoring glucose levels, footcare. The Self-Care Inventory-Revised (SCI-R) is valid for use in people with T2DM in the US. Our aim was to determine its suitability for use in the UK.

Methods: 353 people with T2DM participated in the AT.LANTUS Follow-on study, completing measures of diabetes self-care (SCI-R), generic and diabetes-specific well-being (W-BQ28), and diabetes treatment satisfaction (DTSQ). Statistical analyses were conducted to explore structure, reliability, and validity of the SCI-R.

Results: Principal components analysis indicated a 13-item scale (items loading >0.39) with satisfactory internal consistency reliability (α = 0.77), although neither this model nor any alternatives were confirmed in the confirmatory factor analysis. Acceptability was high (>95% completion for all but one item); ceiling effects were demonstrated for six items. As expected, convergent validity (correlations between self-care behaviours) was found for few items. Divergent validity was supported by expected low correlations between SCI-R total and well-being (rs = 0.02-0.21) and treatment satisfaction (rs = 0.29). Known-groups validity was partially supported with significant differences in SCI-R total by HbA1c (≤ 7.5% (58 mmol/mol): 72 ± 11, >7.5% (58 mmol/mol): 68 ± 14, p < 0.05) and diabetes duration (≤ 16 years: 67 ± 13, >16 years: 71 ± 12, p < 0.001) but not by presence/absence of complications or by insulin treatment algorithm.

Conclusions: The SCI-R is a brief, valid and reliable measure of self-care in people with T2DM in the UK. However, ceiling effects raise concerns about its potential for responsiveness in clinical trials. Individual items may be more useful clinically than the total score.

References

    1. Wright A, Burden AC, Paisey RB, Cull CA, Holman RR. Sulfonylurea inadequacy: efficacy of addition of insulin over 6 years in patients with type 2 diabetes in the U.K. Prospective Diabetes Study (UKPDS 57) Diabetes Care. 2002;25(2):330–336. doi: 10.2337/diacare.25.2.330.
    1. Bradley C, Gilbride CJ. Improving treatment satisfaction and other patient-reported outcomes in people with type 2 diabetes: the role of once-daily insulin glargine. Diabetes Obes Metab. 2008;10(Suppl 2):50–65.
    1. Pouwer F, Snoek FJ, van der Ploeg HM, Ader HJ, Heine RJ. Monitoring of psychological well-being in outpatients with diabetes: effects on mood, HbA(1c), and the patient’s evaluation of the quality of diabetes care: a randomized controlled trial. Diabetes Care. 2001;24(11):1929–1935. doi: 10.2337/diacare.24.11.1929.
    1. Peyrot M, Rubin RR. Levels and risks of depression and anxiety symptomatology among diabetic adults. Diabetes Care. 1997;20(4):585–590. doi: 10.2337/diacare.20.4.585.
    1. Polonsky WH, Fisher L, Guzman S, Villa-Caballero L, Edelman SV. Psychological insulin resistance in patients with type 2 diabetes: the scope of the problem. Diabetes Care. 2005;28(10):2543–2545. doi: 10.2337/diacare.28.10.2543.
    1. Yki-Jarvinen H. Insulin therapy in type 2 diabetes: role of the long-acting insulin glargine analogue. Eur J Clin Invest. 2004;34(6):410–416. doi: 10.1111/j.1365-2362.2004.01356.x.
    1. Davies M, Storms F, Shutler S, Bianchi-Biscay M, Gomis R. Improvement of glycemic control in subjects with poorly controlled type 2 diabetes: comparison of two treatment algorithms using insulin glargine. Diabetes Care. 2005;28(6):1282–1288. doi: 10.2337/diacare.28.6.1282.
    1. Glasgow RE, Osteen VL. Evaluating diabetes education: are we measuring the most important outcomes? Diabetes Care. 1992;15:1423–1432. doi: 10.2337/diacare.15.10.1423.
    1. Johnson SB. Methodological issues in diabetes research. Diabetes Care. 1992;15:1658–1667. doi: 10.2337/diacare.15.11.1658.
    1. Abraham CS, Hampson SE. A social cognition approach to health psychology: philosophical and methodological issues. Psychol Health. 1996;11:223–241. doi: 10.1080/08870449608400254.
    1. Toobert DJ, Hampson SE, Glasgow RE. The summary of diabetes self-care activities measure: results from 7 studies and a revised scale. Diabetes Care. 2000;23(7):943–950. doi: 10.2337/diacare.23.7.943.
    1. La Greca AM, Swales T, Klemp S, Madigan S. Self care behaviors among adolescents with diabetes. Ninth Annual Sessions of the Society of Behavioral Medicine. Baltimore, MD: Society of Behavioural Medicine; 1988. p. A42.
    1. Weinger K, Butler HA, Welch GW, La Greca AM. Measuring diabetes self-care: a psychometric analysis of the Self-Care Inventory-Revised with adults. Diabetes Care. 2005;28(6):1346–1352. doi: 10.2337/diacare.28.6.1346.
    1. Greco P, La Greca A, Ireland S, Wick P, Freeman C, Agramonte R. Assessing adherence in IDDM: a comparison of two methods. Diabetes. 1990;40(Suppl 1):A165.
    1. Fisher E, Greco P, Spetter D, Quillian R, Skyler J, La Greca A. Specific and general characteristics of social support in diabetes care: relationship with adherence and metabolic control. Diabetes. 1991;40(1):538A.
    1. Polonsky WH, Anderson BJ, Lohrer PA, Welch G, Jacobson AM, Aponte JE. Assessment of diabetes-related distress. Diabetes Care. 1995;18(6):754–760. doi: 10.2337/diacare.18.6.754.
    1. Speight J, Barendse S, Bradley C. Further development of the well-being questionnaire to include diabetes-specific as well as generic subscales and new stress subscales. Proc British Psychological Soc. 2000;8(1):21.
    1. Bradley C. The 12-item well-being questionnaire: origins, current stage of development, and availability. Diabetes Care. 2000;23(6):875. doi: 10.2337/diacare.23.6.875.
    1. Bradley C. In: Handbook of psychology and diabetes. Bradley C, editor. Chur, Switzerland: Harwood Academic Publishers; 1994. Diabetes treatment satisfaction questionnaire (DTSQ) pp. 111–132.
    1. Kline P. The handbook of psychological testing. London: Routledge; 1993.
    1. Bentler PM, Bonett DG. Significance tests and goodness of fit in the analysis of covariance structures. Psychol Bull. 1980;88:588–606.
    1. Bentler PM. Comparative fit indexes in structural models. Psychol Bull. 1990;107(2):238–246.
    1. Tucker LR, Lewis C. A reliability coefficient for maximum likelihood factor analysis. Psychometrika. 1973;38:1–10. doi: 10.1007/BF02291170.
    1. Browne MW, Cudeck R. In: Testing structural equation models. Bollen KA, Long JS, editor. Newbury Park, CA: Sage; 1993. Alternative ways of assessing model fit; pp. 136–162.
    1. Schumaker RE, Lomax RE. A Beginner’s guide to structural equation modeling. Hilsdale, NJ: Lawrence Erlbaum Associates; 1996.
    1. Orme CM, Binik YM. Consistency of adherence across regimen demands. Heal Psychol. 1989;8:27–43.
    1. Rubin RR, Peyrot M. Psychosocial problems and interventions in diabetes. A review of the literature. Diabetes Care. 1992;15(11):1640–1657. doi: 10.2337/diacare.15.11.1640.
    1. Speight J, Bradley C. The ADKnowl: identifying knowledge deficits in diabetes care. Diabet Med. 2001;18(8):626–633. doi: 10.1046/j.1464-5491.2001.00537.x.
    1. Hebert JR, Ma Y, Clemow L, Ockene IS, Saperia G, Stanek EJ III. Gender differences in social desirability and social approval bias in dietary self-report. Am J Epidemiol. 1997;146(12):1046–1055. doi: 10.1093/oxfordjournals.aje.a009233.
    1. Kristal AR, Andrilla CH, Koepsell TD, Diehr PH, Cheadle A. Dietary assessment instruments are susceptible to intervention-associated response set bias. J Am Diet Assoc. 1998;98(1):40–43. doi: 10.1016/S0002-8223(98)00012-1.
    1. Jaeschke R, Singer J, Guyatt GH. Measurement of health status. Ascertaining the minimal clinically important difference. Control Clin Trials. 1989;10(4):407–415. doi: 10.1016/0197-2456(89)90005-6.
    1. US Department of Health and Human Services FDA Center for Drug Evaluation and Research, US Department of Health and Human Services FDA Center for Biologics Evaluation and Research, US Department of Health and Human Services FDA Center for Devices and Radiological Health. Guidance for industry: patient report outcome measures: use in clinical medical product development to support labelling claims: draft guidance. HQLO. 2006;4(79) doi: 10.1186/1477-7525-4-79.
    1. US Department of Health and Human Services FDA Center for Drug Evaluation and Research, US Department of Health and Human Services FDA Center for Biologics Evaluation and Research, US Department of Health and Human Services FDA Center for Devices and Radiological Health. Guidance for industry: patient-reported outcome measures: use in medical product development to support labeling claims. 2009. .

Source: PubMed

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