Length of stay, discharge disposition, and hospital charge predictors

AORN Journal, May, 2004 by Cynthia D. Epps

When chronic osteoarthritis (OA) results in increasing pain and disability, surgical procedures, such as joint arthroplasty, may be considered. The most recent survey of hospital discharges from the National Center for Health Statistics estimates that approximately 486,000 total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) are performed yearly. (1) Given the pressure to decrease costs by discharging patients more quickly after surgery, it is important to identify factors that lead to a shorter acute care length of stay (LOS), discharge to home instead of discharge to a subacute or rehabilitation unit, and decreased hospital charges. These factors, which are physiological and psychosocial variables that affect desired outcomes, can be classified as patient factors, clinical factors, and treatment factors.

Patient factors include age, gender, race, and living arrangement. These factors are either nonmalleable traits or pre-existing states that each patient possesses before joint replacement surgery. Clinical factors include comorbidities and preoperative physical status indicators (eg, total lymphocyte count [TLC], hematocrit). Body mass index (BMI), an indicator of total body fat, also is a relevant clinical indicator because joint stress can be caused by an increased BMI. Treatment factors include surgical factors, such as length of time in surgery and type of anesthesia, and postoperative factors, such as type and amount of postoperative analgesia and postoperative complications.

PURPOSE AND SIGNIFICANCE

The purpose of this study was to explore the effect of patient, clinical, and treatment factors on LOS, discharge disposition, and total acute care hospital charges for older adults undergoing elective THA or TKA. Older adults were defined as people 60 years of age or older.

HUMAN COSTS. One group of researchers reported that the success rate of joint replacement surgery for reducing pain and increasing function is greater than 90%. (2) As OA continues to cause disability and pain in an increasing population of older adults, more arthroplasties will be performed. At the same time, reimbursement pressures will continue to press acute care facilities to decrease LOS and costs and to discharge patients quickly.

FINANCIAL COSTS. Despite efforts to curtail reimbursements, the cost of health care in the United States continues to rise. In 1995, $988 billion (ie, 13.6% of the gross domestic product) was spent for health care. (3) Two researchers note that hospital costs account for the largest portion (ie, 35.4%) of health care expenditures, (3) and THAs and TKAs are noted to be high volume procedures with a high cost per case. (4) Additionally, nurse shortages in intensive care units, ORs, and postanesthesia care units are expected to increase, which also will contribute to the rising cost for these procedures. (5) Meanwhile, decreasing the LOS is increasing patient acuity and, therefore, nursing responsibility, compounding the effects of the nursing shortage.

SIGNIFICANCE FOR NURSING. Health care providers, including nurses and physicians, need to identify the variables that influence outcomes in knee and hip arthroplasties to link quality of care with cost of care. Improvements in patient education, discharge planning, and posthospital adjustment can be identified after predictor variables are known and an analysis of patient outcomes is performed. (6) One major result of outcome research is the implementation of care delivery models grounded in research and based on data that are patient-centered, measurable, and associated with standards of care. Such delivery models lead to increased satisfaction for nurses, physicians, and patients. (6,7)

RESEARCH QUESTIONS

The following research questions were addressed in this study.

* What are the differences in patient, clinical, and treatment factors in older patients who undergo THA and TKA and are discharged to subacute units compared to those discharged to home?

* Do patient, clinical, and treatment factors contribute to LOS, discharge disposition, and hospital charges in older adults undergoing elective THA or TKA?

LITERATURE REVIEW

A number of studies have examined patient, clinical, and treatment factors related to THAs and TKAs. All of the studies reviewed a variety of patient, clinical, and treatment factors as possible correlates or predictors of the outcome variables.

LENGTH OF STAY--PATIENT FACTORS. Patient factors that have been studied include age, gender, race, and living arrangement. Results are contradictory, so no clear conclusions about the impact of patient factors on LOS can be drawn. One group of researchers found no significant differences in LOS between younger and older matched groups of patients who underwent THA or TKA. (8) Another group of researchers also found no correlation between LOS and age in a group of patients 80 years old or older who underwent THA. (9) In contrast, another study of matched groups of older and younger patients undergoing THA found that patients in the older group had an average LOS that was two days longer than patients in the younger group. (10) One study significantly correlated age with LOS in patients who underwent THA and TKA, with older patients having increased LOS. (2) Finally, a large Finnish study of 15,461 patients who underwent THA and TKA also found increased age predicted increased LOS. (11)