Process versus Outcome Measures

Measures for achieving the goal of the improvement effort can be an outcome (e.g., mortality, morbidity, length of stay), a process, (e.g., β-blockers in patients suffering a myocardial infarction), or perception of care (e.g., patient satisfaction, health-related quality of life as experienced and reported by patients or their surrogates).^{[9] [61]} There is a significant debate regarding whether to measure processes or outcomes of care.^[28] Process measures are acceptable to caregivers because they demonstrate the degree to which caregivers can influence a process with the intention to improve patient outcomes. Providers feel more accountable for the process of care than its outcomes, which are affected by many other variables. ^[28] Process measures that are incorporated into routine clinical data collection also provide a constant educational reminder to clinicians about the correct process and eliminate duplicate data collection for quality assessment. Joint efforts among providers, professional societies, and external government or payer agencies to develop and maintain process measures have made them more feasible. To be valid, process measures should have causal links to important outcomes. A change in the process should produce a desired change in outcomes without other influences.

Patients and purchasers usually care about outcomes rather than processes. Implementing process measures can be difficult because they require frequent updating as the science of medicine advances. Because of the need for risk adjustment and long-term follow-up in some cases, the data collection burden is often greater for outcome measures. For patients with chronic diseases, these longer-term outcomes are increasingly important. If the outcome occurs infrequently, it will take considerable time before providers can obtain meaningful feedback. For example, evidence of improved rates of catheter related blood-stream infections may require 3 months of data, whereas improved adherence to evidence-based processes to reduce infections may be observed within a week.

Evaluating the quality of a process of care requires determination of whether clinicians adhered to practices that are important to achieving the best outcomes for similar patients. The linkage of practice to outcomes must be previously demonstrated scientifically or must be widely accepted by peers, although the latter risks being accepted but wrong. In general, a balanced set of process and outcome measures helps to inform improvement efforts and provides evidence that efforts made a difference in the lives of patients.