BACKGROUND/RATIONALE:
Despite the societal and personal impact of amputations in persons with diabetes, research in this area has been extremely limited, and has not resulted in a definitive analysis that can demonstrate that amputation rates among VHA clinical users of VHA care have decreased. Challenges to doing so include definition of cohorts, risk adjustment, ascertainment of amputation and characterization of amputation.

OBJECTIVE(S):
Aim 1. Analyze incident non-traumatic LEAs among VHA clinical users with diabetes using multiple years of the matched VHA and Medicare data.
Aim 2. Analyze longitudinal trends in risk adjusted incident annual amputations among VHA clinical users with diabetes.
Aim 3. Analyze risk of and time to repeat amputations and medical outcomes (stroke, dialysis, and death) among diabetic veterans identified with incident LEAs during study the period.
Aim 4. Evaluate the association between initial non-traumatic major amputation and the use of lower extremity bypass surgery and angioplasty by diabetic VA clinical users.

METHODS:
The basic design of the study was a retrospective inception cohort. Under this approach, inception cohorts were identified with data from FY 1999 (10/1/1998) through FY 2003 (9/30/2003) and followed through the end of FY 2004 (9/30/2004). Because the inception cohort was identified from FY 1999 through FY 2003, the follow up period of VHA clinical users varied from a minimum of 1 year to a maximum of 5 years.


FINDINGS/RESULTS:
1. Initial Lower Extremity Amputations (ILEAs): Compared with any amputations in fiscal year 2000, 12-, 18-, and 24-month look-back period decreased the ILEA rates by 19%, 24%, and 27%, respectively. The extent of identification was most complete with 24 months prior data, with marginal gains in extending the prior observation period from 18 to 24 months. (Sambamoorthi et al, 2006).
2. Regional Variation in Amputations: Simultaneous evaluation of major and minor amputation rates identifies different patterns of regional outlier status compared to total or major amputation rates alone. This strategy may facilitate targeted evaluations of health-care processes and structures (Tseng et al, 2007a).
3. Individual Level Predictors Of Amputations: After controlling for other independent variables, a five-point increase in MCS score was associated with a 5% decrease in the risk of major lower extremity amputations (LEAs) (odds ratio [OR]=0.95; 95% confidence interval [95% CI]=[0.94, 0.96]) but was not related to minor LEAs (OR=1.01; 95% CI=[0.97, 1.05]). (Tseng et al, 2007b).


IMPACT:
Our findings are highly relevant to VA and non-VA policy-makers. A strong association was found between continuity of foot care surveillance and improved mental health functioning and decreased major amputations, consistent with the mission of the VA Prevention, Amputation Care and Treatment Program.

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External Links for this Project

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PUBLICATIONS:

Journal Articles

1. Tseng CL, Helmer D, Rajan M, Tiwari A, Miller D, Crystal S, Safford M, Greenberg J, Pogach L. Evaluation of regional variation in total, major, and minor amputation rates in a national health-care system. International journal for quality in health care : journal of the International Society for Quality in Health Care / ISQua. 2007 Dec 1; 19(6):368-76. [view]
2. Sambamoorthi U, Tseng CL, Rajan M, Anjali T, Findley PA, Pogach L. Initial nontraumatic lower-extremity amputations among veterans with diabetes. Medical care. 2006 Aug 1; 44(8):779-87. [view]
3. Tseng CL, Sambamoorthi U, Helmer D, Tiwari A, Rosen AK, Rajan M, Pogach L. The association between mental health functioning and nontraumatic lower extremity amputations in veterans with diabetes. General hospital psychiatry. 2007 Nov 7; 29(6):537-46. [view]

Conference Presentations

1. Tseng CL, Helmer D, Wrobel J, Rajan M, Tiwari A, Sambamoorthi U, Pogach LM. Association of visits to podiatrists and risk of death without initial major amputation among patients with diabetes. Paper presented at: American Podiatric Medical Association Annual Meeting; 2008 Jul 24; Oahu, HI. [view]
2. Tseng CL, Helmer D, Wrobel J, Rajan M, Tiwari A, Sambamoorthi U, Pogach LM. Differential association between footcare and risk of initial amputation among patients with diabetes and defined foot conditions. Poster session presented at: AcademyHealth Annual Research Meeting; 2008 Jun 8; Washington, DC. [view]
3. Tseng CL, Rajan M, Miller DR, LaFrance JP, Pogach L. Racial-ethnic trends in initial lower extremity amputation rates among Veterans Health Administration Heath Care System users from 2000 to 2004. Paper presented at: VA HSR&D Field-Based Equity Conference; 2010 Sep 13; Boston, MA. [view]
4. Tseng C, Rajan M, Miller DR, Lafrance JP, Pogach LM. Trends in Initial Lower Extremity Amputation Rates among Veterans Health Administration Health Care System Users from 2000 to 2004. Poster session presented at: VA HSR&D National Meeting; 2011 Feb 17; National Harbor, MD. [view]

DRA: Health Systems Science
DRE: Epidemiology
Keywords: Diabetes, Practice patterns, Utilization patterns
MeSH Terms: none