We sought to determine the short-term impact of the CASMP on costs associated with CSA-related illness, compared with usual care, at three months from baseline. One-hundred thirty participants were assigned to the six-week CASMP or usual care via centrally controlled, computerized randomization. Cost data were collected using the AHCR. We found that the CASMP did not significantly impact CSA-related costs at three months. Two factors may account for this finding. First, indirect costs were the major contributor to costs, accounting for nearly two-thirds of the total. These indirect costs estimated the value of all unpaid time spent by participants themselves as well as unpaid caregivers (eg, family members, friends or neighbours) engaged in caregiving practices, including direct patient care, attending health care appointments and performing household work that would otherwise be performed by the patient, were it not for his/her angina. Throughout the course of the CASMP, various self-management strategies known to enhance one’s capacity for chronic condition self-management are rehearsed and integrated. At three months, participants would likely still have been experimenting with the various angina pain self-management strategies offered to determine which strategies best fit their lifestyles and short-term goals. More time may therefore be required to observe significant reductions in indirect costs as a function of participants’ enhanced capacity to manage their angina day to day.
A second potential reason for our finding pertains to the makeup of system costs derived. System costs in the present study included those paid by OHIP and the costs borne by private insurers for time spent by health care professionals caring for participants (in either the home or the clinic setting). Over the course of the study, participants attended previously scheduled follow-up visits with their primary care providers and/or cardiologists. A portion of these visits contributed to our cost estimates because they fell within the four-week recall period at follow-up data collection. The CASMP could therefore not have reduced costs related to these prearranged appointments. However, as with indirect costs, there is potential for the CASMP to significantly reduce health service costs in the longer term, which has been demonstrated with other self-management programs. For example, in a four-year examination of an arthritis self-management program in the United States, Lorig et al (33
) found that physician visits were reduced by a mean of 40%. Mean cost savings of $648 and $189 per patient were also found (33
) for those living with rheumatoid arthritis and osteoarthritis, respectively (33
). These significant cost savings occurred over the longer term, once self-management skills taught had been integrated as a routine part of daily life (33
As a secondary objective, we estimated the total mean annualized cost of illness for CSA patients at $19,209 per person from 2003 to 2005. This annualized cost poses a considerable burden at the individual patient level potentially more so than that of other major chronic, debilitating health problems in Canada. For example, using the AHCR, Guerriere et al (34
) estimated the median annualized cost of chronic noncancer pain in Ontario to be $12,700 per person in 2003. The mean age of our angina sample was 68 years, and the majority of patients were retired, with a limited income. Most of the costs incurred were those borne by the patients themselves, along with indirect time costs. Aside from the potential to reduce system-related costs, the CASMP significantly increased HRQL and self-efficacy to manage angina symptoms (21
). It could therefore have a critical role to play in helping these patients decrease direct out-of-pocket expenses and reliance on others, reflected by foregone income due to informal caregiving practices.
The overall economic burden of CSA at the societal level in Canada cannot be extrapolated on the basis of our cost estimates due to our limited sample and restriction of data collection procedures to one region of Ontario. Moreover, our annualized estimate of cost burden must be interpreted with caution. Although annualizing cost data can be helpful for discerning yearly fiscal impact, certain costs can become overinflated. For example, 35% of our sample (n=46) reported one cardiologist visit within our two-month data collection period. By virtue of annualizing, these participants may appear to have seen a cardiologist six times over the course of one year. However, this inflation can arguably (but not certainly) be balanced by the fact that those participants who did not report seeing a cardiologist (n=84) within our two-month data collection period appeared as though they had never seen a cardiologist over the course of one year.
Although annualizing can introduce further variation to some cost estimates, the vast majority (two-thirds) of our estimated costs were indirect costs. These costs are less likely to be prone to inflation by annualizing. Indirect costs estimated the value of all unpaid time spent by participants engaged in angina caregiving-related practices. These day-to-day costs are unlikely to have varied significantly from month to month, given that our sample was a stable and chronic illness population. Ideally, a more robust annual estimate of cost burden should be produced in a subsequent, long-term study wherein monthly cost data can be collected for one year.
Despite the potential for our estimated annual costs to inflate the true annual burden of angina, it has been demonstrated that up to 59% of Canadians with heart disease aged over 12 years report activity restriction compared with those without heart disease (17
). Given that CSA is a cardinal symptom of ischemic heart disease, the cumulative cost burden of CSA to Canadian society is likely considerable. In the United Kingdom, for example, the direct cost of CSA in 2000, including prescriptions, admissions, outpatient referrals and procedures, was estimated to be £669,000,000, accounting for 1.3% of the total National Health Service expenditure (35
To our knowledge, our study is the only study to date that has examined CSA-related costs at the patient level. The importance of this contribution lies with the comprehensiveness of our cost estimates using the societal perspective, including direct out-of-pocket costs, indirect time costs and system costs. Although estimates were based on self-report data, previous work by Guerriere et al (25
) has demonstrated strong psychometric properties of the AHCR, with almost perfect agreement between participants’ responses and hospital, pharmacy and physician records (kappa = 0.41; 95% CI 0.16 to 0.61). Our current estimate of the economic burden, at $19,209 per annum per patient, makes a compelling case for a large-scale examination of the cost burden of CSA in Canada, beyond the context of the Ontario health care system and our limited data collection period.
With the growing global burden of angina and heart disease, nongovernmental organizations in Canada, the United States and abroad have stressed the need for advancements in cost-effective secondary prevention strategies (17
). Given the magnitude of the per-patient burden that our initial CSA cost-related findings suggest, and given the evidence to suggest that self-management training can reduce costs over the longer term, further research is warranted to evaluate the long-term potential of the CASMP to reduce the cost of illness for CSA patients.