Researchers have documented a strong inverse relation between health and socioeconomic status (SES) in developed countries, such as the United States (Banks et al., 2006; Smith, 2004). However, this relationship is not well established in developing countries like India (Zimmer and Amornsirisomboon, 2001). Further, recent literature suggests that the direction of association between cardiac health and SES in such developing countries may be opposite of what is observed in the developed world; that is, higher SES is associated with increased risk of poor cardiac health (Reddy, 2002; Reddy et al., 2007). As regional and national economies in India continue to expand, the consumption basket of many individuals is changing, leading to dietary changes and increased obesity that pose risks to cardiac health (Subramanian and Smith, 2006). This phenomenon has been documented in other developing countries, such as Brazil, China, and Russia, as well as south Asian countries such as India, Sri Lanka, and Thailand (Monteiro et al., 2004; World Health Organization, 2002).
From recently collected data in the Longitudinal Aging Study in India (LASI) pilot study, we examine SES gradients in cardiovascular health of older Indians across four states using both self-reports and health markers measured at the time of the interview. Self-reports of diagnosed medical conditions are tied to access to healthcare services and, therefore, can mask undiagnosed conditions (Lee and Smith, 2011; Smith, 2007a, 2007b). In countries like India where access to healthcare is limited, the prevalence of undiagnosed conditions is expected to be greater than in developed countries. The use of biomarkers enables us to study health outcomes without self-report biases that may be differentially associated with SES and access to health services. These biomarker measures may also provide additional insights into true disease prevalence as well as the extent of undiagnosis and good management of chronic diseases in India.
The study sample is drawn from the pilot survey of LASI. LASI is designed to be a panel survey representing persons at least 45 years of age in India and their spouses. The pilot study was fielded in four states: Karnataka, Kerala, Punjab, and Rajasthan. These four states were chosen to capture not only regional variations, but also socioeconomic and cultural differences. Punjab is an example of a relatively economically developed state located in the north, while Rajasthan, also in the north, is relatively poor. The southern state of Kerala, which is known for its relatively efficient healthcare system and high literacy rate (Shetty and Pakkala,