Abstract
Purpose
The purpose of this study was to develop and evaluate the psychometric properties of (a) a glaucoma medication self-efficacy scale and (b) a glaucoma outcome expectations scale.
Patients and Methods
Two instruments were developed: a glaucoma medication self-efficacy scale and a glaucoma outcome expectations scale. Packets containing (a) the instruments and patient demographic questions and (b) a letter explaining the study were distributed to 225 glaucoma patients from three ophthalmology practices between August and December 2007. The instrument was completed by 191 patients for a response rate of 85%. Principal components factor analysis with a varimax rotation and Cronbach's α reliability were used to analyse the data. To assess discriminant validity, we administered the scales and two self-reported measures of adherence in a separate sample of 43 glaucoma patients who were currently using at least one glaucoma medication.
Results
Our results yielded a 21-item self-efficacy in overcoming barriers that might interfere with the use of glaucoma medications scale, a 14-item self-efficacy in carrying out specific tasks required to use eye drops correctly scale, and a four-item glaucoma outcome expectations scale. Results of the Cronbach's α reliability indicated that the scales are internally consistent. The self-efficacy scales were both significantly associated with two patient self-reported measures of glaucoma medication adherence, which show discriminant validity.
Conclusions
Eye care providers and researchers can use these scales to identify patients with low self-efficacy in using their glaucoma medications and patients who do not believe that following their eye care providers’ advice can help their vision.
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References
Glaucoma Research Foundation. Glaucoma Facts and Stat. Available athttp://www.glaucoma.org/learn/facts.html, 2005.
Pizzarello L, Abiose A, Ffytche T, Duerksen R, Thulasiraj R, Taylor H et al. VISION 2020: the right to sight: a global initiative to eliminate avoidable blindness. Arch Ophthalmol 2004; 122 (4): 615–620.
Gordon MO, Beiser JA, Brandt JD, Heuer DK, Higginbotham EJ, Johnson CA et al. The ocular hypertension treatment study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol 2002; 120 (6): 714–720.
Higginbotham EJ, Schuman JS, Goldberg I, Gross RL, Van Denburgh AM, Chen K et al. Bimatoprost Study Groups 1 and 2: one-year, randomized study comparing bimatoprost and timolol in glaucoma and ocular hypertension. Arch Ophthalmol 2002; 120: 1286–1293.
Camras CB, The United States Latanoprost Study Group. Comparison of latanoprost and timolol in patients with ocular hypertension and glaucoma: a six-month, masked multicenter trial in the United States. Ophthalmology 1996; 103: 138–147.
Buller AJ, Connell B, Spencer AF . Compliance: clear communication's critical. Br J Ophthalmol 2005; 89: 137.
Nordstrom BL, Friedman DS, Mozaffari E, Quigley HA, Walker AM . Persistence and adherence with topical glaucoma therapy. Am J Ophthalmol 2005; 140 (4): 598–606.
Schwartz GF, Platt R, Reardon G, Mychaskiw MA . Accounting for restart rates in evaluating persistence with ocular hypotensives. Ophthalmology 2007; 114: 648–652.
Robin AL, Stone JL, Sleath B, Covert DW, Cagle GD . An objective evaluation in glaucoma patients of eye-drop instillation using video observations patient surveys. Presentation, American Glaucoma Society Annual Meeting, 2008.
Sleath B, Robin A, Byrd J, Covert D, Tudor G . Glaucoma patient receipt of information and instruction on how to use their eye drops. Intl J Pharm Practice 2008; 16: 35–40.
Baranowski T, Perry CL, Parcel GS . How individuals, environments, and health behavior interact: social cognitive theory. In: Glanz K, Rimer BK, Lewis FM (eds). Health Behavior and Health Education. John Wiley & Sons: Hoboken NJ, 2002, pp 165–184.
Bandura A . Social Foundation of Thought and Action: A Social Cognitive Theory. Prentice-Hall: Englewood Cliffs NJ, 1986.
Bandura A . Human agency in social cognitive theory. Am Psychol 1998; 44 (9): 1175–1184.
DeVellis BM, DeVellis RF . Self-efficacy and health. In: Baum A and Revenson TA (eds). Handbook of Health Psychology. Lawrence Erlbaum: NY, 2001, pp 235–248.
Parsons JT, Rosof E, Mustanski B . Medication adherence mediates the relationship between adherence self-efficacy and biological assessments of HIV health among those with alcohol use disorders. AIDS Behav 2008; 12 (1): 95–103.
Sarkar U, Fisher L, Schillinger D . Is self-efficacy associated with diabetes self-management across race/ethnicity and health literacy? Diabetes Care 2006; 29 (4): 823–829.
Burra TA, Chen E, McIntyre RS, Grace SL, Blackmore ER, Stewart DE . Predictors of self-reported antidepressant adherence. Behav Med 2007; 32: 127–134.
Skaff MM, Mullan JT, Fisher L, Chesla CA . A contextual model of control beliefs, behavior, and health: Latino and European Americans with Type 2 diabetes. Psychol Health 2003; 18 (3): 295–312.
Johnson MO, Catez SL, Remien RH, Rotheram-Borus MJ, Morin SF, Charlebois E et al. Theory guided, empirically support avenues for intervention on HIV medication non-adherence: findings from the healthy living project. AIDS Patient Care STDs 2003; 17: 645–656.
Clark NM, Rakowski W, Wheeler JR, Ostrander LD, Oden S . Development of self-management education for elderly heart patients. Gerontologist 1988; 28 (4): 491–494.
Bonner S, Zimmerma BJ, Evans D, Irigoyen M, Resnick D, Mellins RB . An individualized intervention to improve asthma management among urban Latino and African-American families. J Asthma 2002; 39: 167–179.
Holden G, Wade S, Mitchell H, Ewart C, Islam S . Caretaker expectations and the management of pediatric asthma in the inner city: a scale development study. Soc Work Res 1998; 22: 51–59.
Ogedegbe G, Mancuso CA, Allegrante JP, Charlson ME . Development and evaluation of a medication adherence self-efficacy scale in hypertensive African-American patients. J Clin Epidemiol 2003; 56: 520–529.
Strecher VJ, DeVellis BM, Becker MH, Rosenstock IM . The role of self-efficacy in achieving health behavior change. Health Educ Q 1986; 13 (1): 73–92.
Horan Ml, Kim KK, Gendler P, Froman RD, Patel MD . Development and evaluation of the osteoporosis self-efficacy scale. Res Nurs Health 1998; 21 (5): 395–403.
Lorig K, Chastain RL, Ung E, Shoor S, Holman HR . Development and evaluation of a scale to measure perceived self-efficacy in people with arthritis. Arthritis Rheum 1989; 32 (1): 37–44.
Tobin DL, Wigal JK, Winder JA, Holroyd KA, Creer TL . The ‘asthma self-efficacy scale. Ann Allergy 1987; 59 (4): 273–277.
Wigal JK, Creer TK, Kotses H . The COPD seld-efficacy scale. Chest 1991; 99 (5): 1193–1196.
Moens A, Grypdonck MHF, van der Bijl JJ . The development and psychometric testing of an instrument to measure diabetes management self-efficacy in adolescents with type 1 diabetes. Scholarly inquiry for nursing practice. Int J 2001; 15 (3): 223–233.
Rapley P, Passmore A, Phillips M . Review for the psychometric properties of the diabetes self-efficacy scale: Australian longitudinal study. Nurs Health Sci 2003; 5: 289–297.
Day DG, Sharpe ED, Atkinson MJ, Stewart JA, Stewart WC . The clinical validity of the treatment satisfaction survey for intraocular pressure in ocular hypertensive and glaucoma patients. Eye 2006; 20: 583–590.
Sleath B, Robin AL, Covert D, Byrd JE, Tudor G, Svarstad B . Patient-reported behavior and problems in using glaucoma medications. Ophthalmology 2006; 113 (3): 421–436.
Tsai JC, McClure CA, Ramos SE, Schlundt DG, Pichert JW . Compliance barriers in glaucoma: a systematic classification. J Glaucoma 2003; 12 (5): 393–398.
Taylor SA, Galbraith S, Mills RP . Causes of non-compliance with drug regimens in glaucoma patients: a qualitative study. J Ocul Pharmacol Ther 2002; 18: 401–409.
Winfield AJ, Jessiman D, Williams A, Esakowitz L . A study of the causes of non-compliance by patients prescribed eye-drops. BR J Ophthalomol 1990; 74: 477–480.
Portney LG, Watkins MP . Foundations of Clinical Research: Applications to Practice. Prentice Hall: New Jersey, 2000.
Devellis RG . Scale Development: Theory and Applications. Sage Publications: Newbary Park, 1991.
Morisky DE, Green LW, Levine DM . Concurrent and predictive validity of a self-reported measure of medication adherence. Med Care 1986; 24: 67–74.
McDowell I, Newell C . Measuring Health: A Guide to Rating Scales and Questionnaires. Oxford University Press: New York, 1996.
Nu DP, Steinke DT, Williams LK, Austin R, Lafata JE, Divine G et al. Adherence analysis using visual analog scale versus claims-based estimation. Ann Pharmacother 2007; 41 (11): 1792–1797.
Amico KR, Fisher WA, Cornman DH, Shuper PA, Redding CG, Konkle-Parker DJ et al. Visual analog scale of ART adherence: association with 3-day self-report and adherence barriers. J Acquir Immune Defic Syndr 2006; 42 (4): 455–459.
Ivanova JI, Birnbaum HG, Hsieh M, Yu AP, Seal B, van der Molen T et al. Adherence to inhaled corticosteroid use and local adverse events in persistent asthma. Am J Manag Care 2008; 14 (12): 801–809.
Zeller A, Ramseier E, Teagtmeyer A, Battegay E . Patients’ self-reported adherence to cardiovascular medication using electronic monitors as comparators. Hypertens Res 2008; 31 (11): 2037–2043.
The Eye Diseases Prevalence Research Group. Causes and prevalence of visual impairment among adults in the United States. Arch Ophthal 2004; 122: 477–485.
Ostermann J, Sloan FA, Herndon L, Lee PP . Racial differences in glaucoma care. the longitudinal pattern of care. Arch Ophthal 2005; 123: 1693–1698.
Mason RP, Kosoko O, Wilson MR, Martone JF, Cowan Jr CL, Gear JC et al. National survey of the prevalence and risk factors of glaucoma in St. Lucia, West Indies: Part 1: prevalence findings. Ophthalmology 1989; 96 (9): 1363–1368.
Herndon LW, Brunner TM, Rollins JN . The Glaucoma Research Foundation Patient Survey: patient understanding of glaucoma and its treatment. Am J Ophthalmol 2006; 141: 22–28.
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Sleath, B., Blalock, S., Robin, A. et al. Development of an instrument to measure glaucoma medication self-efficacy and outcome expectations. Eye 24, 624–631 (2010). https://doi.org/10.1038/eye.2009.174
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DOI: https://doi.org/10.1038/eye.2009.174
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