The Prevalence of Comorbid Chronic Disease in Virginia's Adult Patient Population during the Years 2001 and 2004

Objective: Chronic disease comor%idities, on the rise in the U.S. and Virginia, represent a new challenge to the way medicine is practiced and prescribed. This descriptive study uses Virginia hospital discharge data to describe the prevalence and trends of chronic disease comorbidities present in the state's over-45 population during the years 2001 and 2004 Methods: Data collected by Virginia Health Information was utilized. Adults over the age of 45 years and who selected for race and location were included in this analysis, with an aggregate sample size of 813,336 (N=458,593 [2001]; N=364,743 [2004]). Pearson chi-square analyses determined significant sample population differences with respect to age, race, sex, location, number of diagnoses (up to 9) and number of chronic comorbid conditions (up to 7). Binary logistic regression predicted odds ratios (ORs) for these comorbid conditions across demographic variables. SPSS 13.0 was used for all analysis. Results: Chronic comorbidities and their component conditions increased in Virginia's inpatient population from 2001 to 2004. Chronic cardiovascular disease (CCV), chronic liver disease (CLV), chronic renal disease (CRN), chronic pulmonary disease (COP), and cerebrovascular degeneration (CCE) comorbidities all increased in diagnoses prevalence (0.3% 1.8%), while cornorbid cancer (CCA) remained constant at 7.4% and cornorbid diabetes (CDI) decreased 0.6%. Mean comorbid diagnoses increased with age. Demographic factors (race, sex, age and location) as well as certain constituent conditions were predictive of one or more comorbidities. Conclusions: In general, the findings of this report complement current chronic disease monitoring data for the Commonwealth of Virginia. While expected comorbidities did exist (e.g. obesity with diabetes), unpredicted findings such as the highly-comorbid "fluid and electrolyte disorders" or the high1 y-comorbid "deficiency anemias" were also noted. Introduction Chronic comorbidity is the occurrence of ostensibly unrelated chronic diseases and reflects the aggregate effect of all clinical conditions in a given Comorbid chronic diseases comprise an increasing number of preventable hospitalizations and a considerable draw on the U.S. economy.3 Almost every family in the nation is adversely affected by chronic disease, either through the direct burden of the illness or through the indirect hardships of longterm care. Heart disease, cancer, asthma and diabetes are the leading causes of death and disability in the United States, accounting for 70 percent of deaths and affecting the quality of life of 125 million Americans, 65 percent of whom are over 65 years Medical comorbidity is prognostic of poor rehabilitation in geriatric patients, malung this disproportionately affected population ever more dependent on an already strained Medicare While successful treatments for symptoms exist, chronic conditions are rarely completely cured.9 A recent study by van Dijk et all0 documents the predictive nature of chronic conditions in elderly mortality but notes the lack of information on the synergistic effects of these diseases. The simultaneous treatment of multiple chronic conditions and underlying causative factors can be problematical for physicians due to the increased risk of adverse drug interactions during polypharmacy. 11.12,13 For this reason quality of care for chronic illnesses has become a more difficult challenge for physicians, as well as a matter of recent public concern.I4 According to the Virginia Department of Health (vDH)'~, an accumulation of risk factors and a lack of prevention persist in mature Virginians. Chronic disease risk factors like poor nutrition, physical inactivity, failed prevention and improper care of existing conditions are linked to an increased length of hospital stay, treatment charges and mortality in ~ i r ~ i n i a . ' ~ , " Unhealthy diet and sedentary lifestyle are also prevalent in over 70 percent of Virginia's population. Overweight and obesity rates have risen for 15 years and contribute to cardiovascular disease (CVD), coronary heart disease (CHD), stroke, diabetes, hypertension, arthritis and some 18,19.20 cancers. Twenty-six percent-of Virginians are hypertensive and 3 1 percent have high cholesterol, increasing their risk of stroke, kidney failure, and C H D . ~ ~ Men reported smoking, drinking, and being overweight while women reported a lack of physical activity. Blacks were more often hypertensive, diabetic and obese while Whites more often had high cholesterol.19 he VDH reports that comorbid cardiovascular disease, cancer, diabetes, renal disease, arthritis and depression are distinct threats to the health of Virginia's elderly.2' Cardiovascular disease disproportionately affects Blacks and those over 65.22 In Virginia, CVD caused over 126,000 hospital admissions and over 35 percent of all deaths in 2002. While precipitating factors remain unknown in more than 40 percent of the cases,23 studies have found that chronic obstructive pulmonary disease (COPD), diabetes, CHD, hypertension and renal insufficiency are common comorbidities to CVD and each ~ t h e r . ~ ~ , ~ * CHD and hypertension are the most common etiologies in the elderly and often coexist with valvular heart disease, depression and dementia.".26 Cancer has remained the second leading cause of death in Virginia since 1950. Approximately 65,000 Virginians died of cancer from 1997 to 2001. 27 Cancer caused over 27,000 hospitalizations costing $670 million in 2002.~' Arthritis, diabetes, obesity, hypertension and depression are all well-documented cancer comorbidi t ie~ .~~ The national prevalence of diagnosed diabetes, which is expected to double by 2 0 5 0 , ~ ~ increased 47 percent from 1997 to 2002 across all sexes, ages and races. These rates were higher in males and Blacks in every age In 2003 diabetes was the seventh leading cause of death in Virginia. Over 385,000 Virginia adults are diabetic, causing over 11,600 hospitalizations in 2002.~' Seventy percent of diabetes-related deaths are due to a comorbid cause (e.g. CVD, hypertension, obesity and overweight, and renal disease). Chronic renal disease (CRD) is prevalent in the aging population and is associated with hypertension, smoking, hypercholesterolemia and obesity. Aging, poor nutrition, diabetes and CVD are coexisting predictors for patients with end-stage renal disease (ESRD) and contribute to the increased progression of CRD and its comorbid complications.3'~32 In older CRD patients heart disease risk factors are strongly associated with risk of death from CVD.'~ Arthritis affects approximately 25 percent of adult Virginians and 55 percent of those over Depression increases the risk of mortality in rheumatoid arthritis (RA).;~ Systemic inflammation due to CHD is the major cause of vascular comorbidity in R A . ~ ~ Depression is a strong determinant of d i s a b i ~ i t ~ . ' ~ up to 65 percent of myocardial infarction patients, 25 percent of cancer patients and 27 percent of stroke patients suffer from depression. Substance abuse disorders are prevalent in depressive patients.37 It is comorbid with both psychiatric and medical illnesses and is prevalent among diabetics, most often in the presence of comorbidities such as coronary artery disease (CAD), chronic arthritis and stroke." The literature on chronic disease comorbidity is limited. The numbers and trends reviewed here are helpful in the discussion of singular chronic disease but fall short of a comprehensive description on the state of chronic comorbidity in Virginia. This investigation is designed to analyze current frequencies and trends in order to provide a clearer picture of the prevalence of chronic diseases in Virginia's mature adults. It is projected that for certain conditions specific demographics, notably age, will be predictive for comorbidity. Findings are expected to confirm the coexistence of previously documented comorbidities (e.g. diabetes with obesity, CVD with hypertension and hypercholesterolemia, cancer with depression, and liver disease with alcohol abuse) as well as less documented comorbidities (e.g. certain conditions with neurodegenerative conditions, psychoses or substance abuse).