Perceived Functional Status Before and Six Months After Coronary Interventions

INTRODUCTION As a disease category, heart disease is the number one cause of death, accounting for 725,192 deaths in the United States in 1999. During that year, ischemic heart disease accounted for 73% of the deaths from all forms of heart disease.¹ Symptomatic coronary artery disease is present in more than 6 million people in the United States. A significant proportion of patients are candidates for a revascularization procedure, such as a coronary intervention, because of unacceptable symptoms or potentially life-threatening lesions. ² Mortality reduction is a widely accepted criterion for demonstrating efficacy in the treatment of coronary artery disease. ³ Coronary heart disease accounted for 529,659 deaths in 1999 ¹, a 54% decline in age-adjusted mortality rates since 1963. ⁴ As mortality decreases, improving the quality of life or functional status for survivors with coronary disease becomes increasingly important. METHODOLOGY The results reported here were part of a larger process improvement initiative designed to evaluate the care received by patients undergoing coronary interventions at three hospitals in an integrated health care delivery system located in a large Midwest city. The team involved in the project is listed in Table 1. To measure patient perception of functional status, the Seattle Angina Questionnaire (SAQ) was administered before and six months after the intervention. The SAQ is a 19-item, self-administered questionnaire that measures five dimensions of coronary artery disease: physical limitation, anginal stability, anginal frequency, treatment satisfaction, and disease perception. The physical limitation subscale provided a list of activities and asked the patient to indicate how much limitation they experienced due to chest pain or chest tightness from angina over the past four weeks. Activities included common activities of daily living such as dressing, walking, showering, and carrying groceries. The anginal stability item asked patients to compare their current amount of chest pain with the previous four weeks. The anginal frequency subscale asked how often they had chest pain overall and how often they took nitroglycerine tablets for their chest pain. The treatment satisfaction subscale included items related to satisfaction with treatment and physician explanations. Last, the disease perception subscale included items related to enjoying life. The SAQ has reported reliability and validity. ³ The Pearson r values for the subscales are: Physical limitation, 0.83; Anginal stability, 0.24; Anginal frequency, 0.76; Treatment satisfaction, 0.81; Disease perception, 0.78. Since the anginal stability subscale is composed of only one item, its reliability cannot be assessed. Criterion-related validity of the SAQ has been demonstrated for specific subscales. Statistical significance was achieved when comparing: The physical limitation subscale to exercise treadmill results; The anginal stability subscale to the presence or absence of unstable angina at the time of angioplasty; The anginal frequency subscale to the number of nitroglycerin refills; The treatment satisfaction subscale to the American Board of Internal Medicine’s patient satisfaction questionnaire; The disease perception subscale to the general health scale of the Short Form-36 (SF-36). Construct validity was reported using the known-group technique. Subscales were stable for individuals who reported no change in their angina. For those patients who reported improved symptoms, statistically significant improvements were seen in the physical limitation, angina stability, angina frequency, and disease perception subscales. For those patients who reported worsened symptoms, statistically significant decreases were seen in the physical limitation, angina stability, angina frequency, and disease perception subscales. ^3,4 Additional reliability and validity measures have been applied to the tool. ⁵ An algorithm developed by Spertus6 was used to score the Seattle Angina Questionnaires. For each subscale, larger numbers indicate greater perceived function or satisfaction. Descriptive and inferential statistics were used for data analysis. RESULTS Between February 1997 and November 1999, 1,882 individuals completed the SAQ prior to their cardiac procedures; 790 individuals (42%) completed and returned the survey six months after their coronary intervention. Those who returned the survey differed from those who did not in terms of age (p<.001 with="" older="" people="" tending="" to="" return="" the="" survey.="" gender="" was="" similar="" in="" both="" groups.="" type="" of="" intervention="" performed="" not="" assessed="" as="" part="" this="" study="" table="" a="" paired="" t="" test="" used="" compare="" pre="" and="" post="" subscales.="" seen="" figure="" perceived="" functional="" status="" improved="" for="" four="" five="" subscales="" decreased="" one="" subscale.="">DISCUSSION This study has multiple limitations. Data were not analyzed to examine differences among the three hospitals. Further, no analysis was conducted based on type of intervention. Instead, all data were aggregated for analysis. In addition, the patients who completed the second SAQ were significantly different from the original cohort of patients. Older people tended to return the survey, skewing the results of this study. No efforts were made to determine the reason for this selective response, although this is an important question for future research. It may be that the younger patients returned to work and their busy lives, limiting their commitment to and time for completing the survey. With this said, significant improvements were reported in functional status related to physical limitations, anginal stability, anginal frequency and disease perception. Patients perceived significant improvements in their quality of life after the coronary intervention. Given the goal of intervention, this finding is not surprising. However, many of the patients in this study were older, with other chronic diseases; as such, the improvements in functional status are heartening. The drop in level of treatment satisfaction is troublesome. The decrease in patient satisfaction may reflect unrealistic patient expectations. They may have been lead to expect an instant cure from clinicians, friends or the media. Coronary intervention, while effective, is not a solitary treatment. In reality, these individuals have a chronic condition that requires them to modify their lifestyle, including making and sustaining difficult dietary changes and exercise patterns. Health care providers must be very clear about the long-term investment needed by these individuals. Staff in the cath lab may contribute to patient understanding by reinforcing the need for these lifestyle changes. Further research is needed in this area, including efforts to describe clinician explanations to patients.

<p>1. National Vital Statistics System. National Vital Statistics Reports 2001; 49(8). Accessed 7/31/02 at www.cdc.gov/nchs /fastats/pdf /nvsr49_08t9.pdf. </p><p>2. Smith SC, Dove JT, Jacobs AK, et al. ACC/AHA Guidelines for Percutaneous Coronary Intervention (Revision of the 1993 PTCA Guidelines). <i>Circulation</i> 2001;103:3019-3041. </p><p>3. Spertus JA, Winder JA, Dewhurst TA, et al. Development and evaluation of the Seattle Angina Questionnaire: A new functional status measure for coronary artery disease. <i>J Am Coll Cardiol</i> 1995; 25:333-341. </p><p>4. National Heart, Lung and Blood Institute. Morbidity and Mortality Chart Book. 1996. U.S. Government Printing Office: Washington, DC. </p><p>5. Spertus JA, Winder JA, Dewhurst TA, Deyo RA, &amp; Fihn SD. Monitoring the quality of life in patients with coronary artery disease. <i>Am J Cardiol</i> 1994;74:1240-1244. </p><p>6. Halperin, E., Ludwig-Beymer, P. &amp; Hefferan, C. Reliability and validity of the Seattle Angina Questionnaire Preliminary Report. The Seventh Annual Naurice M. Nesset Research Forum Presentation Abstracts. 1999. Advocate Health Care: Park Ridge, IL, p. 23. </p><p>7. Spertus J. Scoring of the Seattle Angina Questionnaire. 1993. Medical Outcomes Trust: Boston, MA.</p>