Receipt of Care and Reduction of Lower Extremity Amputations in a Nationally Representative Sample of U.S. Elderly

Diabetes mellitus (DM) is a major cause of morbidity and mortality, accounting for nearly 7 percent of excess mortality in the U.S. elderly, and prevalence continues to increase (Mokdad et al. 2004; Roglic et al. 2005; Cowie et al. 2006;). Lower extremity complications (LECs) are common among persons with DM (Caputo et al. 1994; Williams, Van Gaal, and Lucioni 2002; Jeffcoate and Harding 2003; Bethel et al. 2007;); half of all amputations occur among such persons (Zoorob and Hagen 1997). Nearly 85 percent of amputations are precipitated by foot ulcers among persons with a DM diagnosis (Apelqvist and Larsson 2000). Recommended care guidelines for DM care include foot examinations at each diabetes visit with a comprehensive foot examination performed annually and tight glycemic control (Zoorob and Hagen 1997; American Diabetes Association 2002, 2005, 2006, 2008b, 2009). Annual foot examination and glycemic control adherence rates have improved (Saaddine et al. 2002; Eliasson et al. 2005;), but many persons still do not receive adequate foot care (Apelqvist and Larsson 2000). Nonadherence is generally high and not limited to persons with LECs (Lee et al. 2003; McClellan et al. 2003; McGlynn et al. 2003; Koro et al. 2004; Sloan et al. 2004;). Diabetes education interventions have been associated with decreased risk of lesions on the feet, better self foot care, and reduced risk of ulceration and amputation by up to 50 percent (Litzelman et al. 1993; Mayfield et al. 1998; Rith-Najarian et al. 1998; Reiber and Ledoux 2002; Plank et al. 2003; Lavery, Wunderlich, and Tredwell 2005). These interventions are more effective when performed by a specialist with lower extremity care expertise (Singh, Armstrong, and Lipsky 2005). These interventions may also decrease cost: individuals with a DM diagnosis and foot ulcers tend to incur substantially higher expenditures on personal health care services than do persons with DM without foot ulcers (Ramsey et al. 1999; O'Brien, Patrick, and Caro 2003;). Incremental expenditures of up to U.S.$46,000 per year have been attributed to foot ulcers in persons with osteomyelitis; the cost of a first lower extremity amputation is U.S.$30,000–U.S.$50,000 (Ramsey et al. 1999; Gordois et al. 2003; O'Brien, Patrick, and Caro 2003; Shearer et al. 2003;). Substantial long-term care expenditures are also incurred by individuals with DM and LECs in particular (Ramsey et al. 1999; Gordois et al. 2003; O'Brien, Patrick, and Caro 2003). There is also a cost in terms of lost productivity (American Diabetes Association 2008a). Persons diagnosed with neuropathy have a low life expectancy (Ramsey et al. 1999; Chaturvedi et al. 2001; Faglia, Favales, and Morabito 2001; Jeffcoate and Harding 2003; Cusick et al. 2005;). Ulceration increases risk of death by 85+ percent, while amputation more than doubles mortality risk in persons with DM (Chaturvedi et al. 2001; Cusick et al. 2005;). Given pressures on public budgets, particularly for Medicare, gauging the productivity of health interventions is a high priority. In this study, we used national longitudinal Medicare claims data to examine whether care provided by clinicians specializing in treating DM and DM-related LECs was associated with better health outcomes, measured by the probability of an amputation of part or all of a leg or foot. We studied care received from podiatrists, clinician specialists in diagnosing and treating LECs (“LEC clinician specialists”), podiatrists in combination with LEC specialists, and other clinicians who care for persons with a DM diagnosis but who are not specialized in lower extremity DM complications. We assessed productivity of receipt of services from these health provider types taken individually and in combination.