Incident depression increases medical utilization in Medicaid patients with hypertension

Abstract

Hypertension is an important risk factor for cardiovascular disease and occurs disproportionately among patients with depression. Few studies have rigorously examined outcomes specifically among hypertensive patients with newly diagnosed comorbid depression. Aim: We hypothesized that incident depression would exacerbate hypertensive disease and that this would be evident through greater utilization of medical services than would otherwise occur in the absence of depression. Methods: Claims data for hypertensive patients enrolled in Maryland Medicaid (2005–2010) were used to estimate the change in annualized utilization following incident depression, compared to a matched cohort of hypertensive patients never diagnosed with depression. Multivariate regression was used to adjust for changes in antihypertensive medications, adherence and comorbidity that followed depression onset. Results: While medical utilization increased after incident depression, additional encounters tended to be for nonacute medical care and there was no significant increase in encounters specifically for cardiovascular or hypertension-related conditions. Discussion: The results contribute to the discussion on the relationship between depression and cardiovascular disease and will inform future studies that aim to look at longer term outcomes in patients with hypertension.

Keywords:

• depression
• hypertension
• Medicaid
• medical utilization

Acknowledgements

The Medicaid staff at the Maryland Department of Health and Mental Hygiene graciously provided assistance with the Medicaid enrollment and claims data used in this study.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Comorbid depression is common in cardiovascular disease (CVD); it is a risk factor for coronary heart disease, stroke, peripheral artery disease and heart failure; and it is associated with greater morbidity, mortality and utilization of health care resources when concurrent with these conditions.

• Physiological pathways between heart disease and depression are not well understood, but it is clearer that depression can influence an individual’s health status, influencing the development and progression of CVD through its associations with nonadherence to medications, barriers to care and risk factors such as smoking, drinking, obesity and hypertension.

• It can be difficult to distinguish whether greater utilization by hypertensive patients with depression is directly attributed to depression or whether depression is perhaps more likely to manifest itself among patients with more severe hypertension. Given the uncertainty surrounding the mechanistic relationship between depression and CVD, it is important to utilize longitudinal data with appropriate statistical methods to estimate the more direct impact of depression onset on subsequent utilization of medical services by hypertensive patients. This study used a database of claims for Maryland Medicaid beneficiaries with hypertension between 2005 and 2010 to assess changes in the levels of medical utilization after the onset of depression.

• Adjusting for negative changes in health status or changes in the use of and adherence to hypertensive therapy, depression onset was associated with an average annual increase of 6.9 medical encounters annually (1.2 outpatient hospital encounters, 1.8 visits to ambulatory nonmental health care providers and 3.9 visits to ambulatory mental health care providers, respectively). There was no significant increase in cardiovascular- or hypertension-specific encounters.

• This study informs the discussion on the relationship between depression and CVD (in the context of informing the delivery of cost–effective care) since it is one of few to rigorously examine the burden of depression in patients with hypertension, an important risk factor for the more serious manifestations of CVD. Increased recognition by clinicians that depression can be both a potential barrier to managing hypertension and a potential risk factor for its manifestations can serve to mitigate the burden of these conditions on the patients and the health care system. Reduction in the rate of medical service utilization is an important metric by which to measure progress.