Abstract
Purpose
To evaluate the reliability and validity of the Perceptions About Medications for Diabetes (PAM-D) instrument.
Methods
The item pool was generated from a literature review and 18 focus groups of Type 2 diabetes patients. Surveys were mailed to 1,000 low-income diabetes patients; 362 were returned; 65 of 100 re-test surveys were returned.
Results
This paper uses data from 343 Type 2 respondents. Mean age and age diagnosed were 59 and 48, respectively; 72% female; 52% African American; 51% were taking oral antihyperglycemic agents [OHA] monotherapy, 18% insulin monotherapy, and 28% insulin plus OHA. The initial 66 items were reduced to 37 across nine scales: scheduling flexibility, portability convenience, regimen inconvenience, medication effectiveness, difficulty remembering medications, gastrointestinal, hypoglycemia-related, and weight/edema physical side effects, and emotional side effects. Scale reliabilities ranged from 0.71 to 0.92 (coefficient alpha) and from 0.54 to 0.83 (test–retest coefficient, 37–81-day interval); factor loadings ranged from 0.35 to 0.86 (median, 0.67); significant scale differences across medication groups (insulin, OHA, insulin plus OHA) were consistent with a priori hypotheses.
Conclusions
The PAM-D has substantial reliability and validity in a low-income, inner-city population of Type 2 diabetes patients and may be valuable for understanding multidimensional perceptions driving patients’ treatment preferences.
Similar content being viewed by others
References
Aristides, M., Weston, A. R., FitzGerald, P., Le Reun, C., & Maniadakis, N. (2004). Patient preference and willingness-to-pay for Humalog Mix25 relative to Humulin 30/70: A multicountry application of a discrete choice experiment. Value in Health, 7(4), 442–454.
Rubin, R. R., & Peyrot, M. (2004). Quality of life, treatment satisfaction, and treatment preference associated with use of a pen device delivering a premixed 70/30 insulin aspart suspension (aspart protamine suspension/soluble aspart) versus alternative treatment strategies. Diabetes Care, 27(10), 2495–2497. Erratum in Diabetes Care. 2004 Dec;2427(2412):3032.
Cappelleri, J. C., Cefalu, W. T., Rosenstock, J., Kourides, I. A., & Gerber, R. A. (2002). Treatment satisfaction in Type 2 diabetes: A comparison between an inhaled insulin regimen and a subcutaneous insulin regimen. Clinical Therapeutics, 24(4), 552–564.
Witthaus, E., Stewart, J., & Bradley, C. (2001). Treatment satisfaction and psychological well-being with insulin glargine compared with NPH in patients with Type 1 diabetes. Diabetic Medicine, 18(8), 619–625.
Anderson, R. T., Skovlund, S. E., Marrero, D., et al. (2004). Development and validation of the insulin treatment satisfaction questionnaire. Clinical Therapeutics, 26(4), 565–578.
Cappelleri, J. C., Gerber, R. A., Kourides, I. A., & Gelfand, R. A. (2000). Development and factor analysis of a questionnaire to measure patient satisfaction with injected and inhaled insulin for Type 1 diabetes. Diabetes Care, 23(12), 1799–1803.
Lewis, K. S., Bradley, C., Knight, G., Boulton, A. J., & Ward, J. D. (1988). A measure of treatment satisfaction designed specifically for people with insulin-dependent diabetes. Diabetic Medicine, 5(3), 235–242.
Hayes, R. P., Bowman, L., Monahan, P. O., Marrero, D. G., & McHorney, C. A. (2006). Understanding diabetes medications from the perspective of patients with Type 2 diabetes: Prerequisite to medication concordance. The Diabetes Educator, 32(3), 404–414.
Shikiar, R., & Rentz, A. M. (2004). Satisfaction with medication: an overview of conceptual, methodologic, and regulatory issues. Value in Health, 7(2), 204–215.
Brod, M., Cobden, D., Lammert, M., Bushnell, D., & Raskin, P. (2007). Examining correlates of treatment satisfaction for injectable insulin in Type 2 diabetes: Lessons learned from a clinical trial comparing biphasic and basal analogues. Health and Quality of Life Outcomes, 5, 8.
Horne, R., & Weinman, J. (1999). Patients’ beliefs about prescribed medicines and their role in adherence to treatment in chronic physical illness. Journal of Psychosomatic Research, 47(6), 555–567.
Gordon, K., Smith, F., & Dhillon, S. (2007). Effective chronic disease management: Patients’ perspectives on medication-related problems. Patient Education and Counseling, 65(3), 407–415.
Phatak, H. M., & Thomas, J., III. (2006). Relationships between beliefs about medications and nonadherence to prescribed chronic medications. The Annals of Pharmacotherapy, 40(10), 1737–1742.
Ross, S., Walker, A., & MacLeod, M. J. (2004). Patient compliance in hypertension: Role of illness perceptions and treatment beliefs. Journal of Human Hypertension, 18(9), 607–613.
McHorney, C. A., Schousboe, J. T., Cline, R. R., & Weiss, T. W. (2007). The impact of osteoporosis medication beliefs and side-effect experiences on non-adherence to oral bisphosphonates. Current Medical Research and Opinion, 23(12), 3137–3152.
McHorney, C. A., Hayes, R., Bowman, L., & Myers, J. (2004). Drivers of treatment preference among patients with Type 2 diabetes. Paper presented at: ISPOR ninth annual international meeting, Arlington, VA, USA, May 16–19. Available at http://www.biostat.iupui.edu/Faculty/monahan.aspx.
Berelson, B. (1954). Content analysis. In G. Lindzey (Ed.), Handbook of social psychology (pp. 488–518). Reading, MA: Addison-Wesley.
Aday, L. A., & Cornelius, L. J. (2006). Designing and conducting health surveys: A comprehensive guide (3rd ed.). San Francisco: Jossey-Bass.
Carter, J. S., Pugh, J. A., & Monterrosa, A. (1996). Non-insulin dependent diabetes mellitus in minorities in the United States. Annals of Internal Medicine, 125(3), 221–232.
Karter, A. J., Stevens, M. R., Herman, W. H., et al. (2003). Out-of-pocket costs and diabetes preventive services: The Translating Research Into Action for Diabetes (TRIAD) study. Diabetes Care, 26(8), 2294–2299.
Pogach, L. M., Hawley, G., Weinstock, R., et al. (1994). Diabetes prevalence and hospital and pharmacy use in the Veterans Health Administration (1994). Use of an ambulatory care pharmacy-derived database. Diabetes Care, 21(3), 368–373.
Koro, C. E., Bowlin, S. J., Bourgeois, N., & Fedder, D. O. (2004). Glycemic control from 1988 to 2000 among U.S. adults diagnosed with Type 2 diabetes: A preliminary report. Diabetes Care, 27(1), 17–20.
McHorney, C. A., Ware, J. E., Lu, J. F. R., & Sherbourne, C. D. (1994). The MOS 36-item short-form health survey (SF-36): III. Tests of data quality, scaling assumptions and reliability across diverse patient groups. Medical Care, 32(1), 40–66.
Zwick, R., & Velicer, W. F. (1986). Comparison of five rules for determining the number of components to retain. Psychological Bulletin, 99(3), 432–442.
Nunnally, J. C., & Bernstein, I. H. (1994). Psychometric theory (3rd ed.). New York: McGraw-Hill.
Stewart, A. L., & Ware, J. E. (1992). Measuring functioning and well-being: The medical outcomes study approach. Durham, NC: Duke University Press.
Howard, K. I., & Forehand, G. A. (1962). A method for correcting item-total correlations for the effect of relevant item inclusion. Educational and Psychological Measurement, 22(4), 731–735.
Cronbach, L. J. (1951). Coefficient alpha and the internal structure of tests. Psychometrika, 16, 297–334.
McGraw, K. O., & Wong, S. P. (1996). Forming inferences about some intraclass correlation coefficients. Psychological Methods, 1(1), 30–46.
Hayes, C., & Bowman, L. (2003). Reliability and validity of the treatment flexibility scale. Quality of Life Research, 12, 863.
Hayter, A. J. (1986). The maximum familywise error rate of Fisher’s least significant difference test. Journal of the American Statistical Association, 81(396), 1000–1004.
Barnett, A. H., Jones, D. B., Burden, A. C., et al. (1996). Multicentre study to assess quality of life and glycaemic control of Type 2 diabetic patients treated with insulin compared with oral hypoglycaemic agents. Practical Diabetes International, 13(6), 179–183.
Bradley, C. (1999). Diabetes treatment satisfaction questionnaire: Change version for use alongside status version provides appropriate solution where ceiling effects occur. Diabetes Care, 22(3), 530–532.
Howorka, K., Pumprla, J., Wagner-Nosiska, D., Grillmayr, H., Schlusche, C., & Schabmann, A. (2000). Empowering diabetes out-patients with structured education: Short-term and long-term effects of functional insulin treatment on perceived control over diabetes. Journal of Psychosomatic Research, 48(1), 37–44.
Hirsch, A., Bartholomae, C., & Volmer, T. (2000). Dimensions of quality of life in people with non-insulin-dependent diabetes. Quality of Life Research, 9(2), 207–218.
Petterson, T., Lee, P., Hollis, S., Young, B., Newton, P., & Dornan, T. (1998). Well-being and treatment satisfaction in older people with diabetes. Diabetes Care, 21(6), 930–935.
Redekop, W. K., Koopmanschap, M. A., Stolk, R. P., Rutten, G. E., Wolffenbuttel, B. H., & Niessen, L. W. (2002). Health-related quality of life and treatment satisfaction in Dutch patients with Type 2 diabetes. Diabetes Care, 25(3), 458–463.
Marra, G., & DIAB. & TE.S Project Study Group. (2004). The DIAB. & TE.S Project: How patients perceive diabetes and diabetes therapy. Acta Bio-Medica: Atenei Parmensis, 75(3), 164–170.
Brod, M., Skovlund, S. E., & Wittrup-Jensen, K. U. (2006). Measuring the impact of diabetes through patient report of treatment satisfaction, productivity and symptom experience. Quality of Life Research, 15(3), 481–491.
Cowie, C. C., & Eberhardt, M. S. (1995). Sociodemographic characteristics of persons with diabetes. In National Diabetes Data Group, National Institutes of Health, & National Institute of Diabetes and Digestive and Kidney Diseases (Eds.), Diabetes in America (pp. 85–116, 2nd ed.).
Acknowledgments
This research was funded with support from Eli Lilly & Company. Dr. Hayes is a full-time employee of and owns stock in Eli Lilly & Company, maker of diabetes treatments. This work was initially led by Dr. McHorney when she was Professor of Medicine at the Indiana University School of Medicine. Dr. McHorney is now a Senior Director in U.S. Outcomes Research, Merck & Company Inc. Dr. McHorney is a full-time employee of and owns stock in Merck & Co., Inc., maker of diabetes treatments. We thank the IU Medical Group (IUMG); ResNet, IUMG’s Primary Care Practice-Based Research Network, their staff for creating our data base and mailing the survey; staff of the Regenstrief Medical Record System; and Jackie Baker for coordinating returned surveys. Portions of this manuscript were presented as posters at the annual meetings of International Society of Quality of Life (2006) and International Diabetes Foundation (2006).
Author information
Authors and Affiliations
Corresponding author
Additional information
Requests for PAM-D instrument: Risa Hayes (email: hayes_clarice@lilly.com)
Rights and permissions
About this article
Cite this article
Monahan, P.O., Lane, K.A., Hayes, R.P. et al. Reliability and validity of an instrument for assessing patients’ perceptions about medications for diabetes: the PAM-D. Qual Life Res 18, 941–952 (2009). https://doi.org/10.1007/s11136-009-9510-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11136-009-9510-2