The next step is talking to many people in the field, asking if they understand the questions, asking translators whether the questions can be misunderstood or misinterpreted in different languages or cultures, and working to neutralize any unintended cultural implications. After the qualitative stage of item development, which includes figuring out how to improve the items as much as possible, the quantitative stage begins, which involves research about which items convey the most information over time.
As part of their PROMIS research, Dr. Khanna and colleagues are now working on development and validation of gastrointestinal symptoms in chronic medical conditions, and they have developed a preliminary item bank. They, like other PROMIS research groups, are following the same 18 steps for item development and validation.
Crosswalking is another “non-trivial step in the process,” according to Dr. Fries. The crosswalk estimates the score on a new instrument or on one item from scores on another, and back again. Through crosswalking, the physician “will be able see what [the new score] would have been on the old scale that he is used to. It’s a lot of grunt work. The point is that you are building from the ground up; you are doing everything you can to have better items. You get better instruments from better items,” he says.
In phase 2 of the research, validation studies began. “We are now asking, ‘Are these instruments better than the old instruments?’ That’s the gutsy question to ask,” he says.
Recommended Reading
- Cella D, Riley W, Stone A, et al. The Patient-Reported Outcomes Measurement Information System (PROMIS) developed and tested its first wave of adult self-reported health outcome item banks: 2005-2008. J Clin Epidemiol. 2010;63:1179-1194.
- Irwin DE, Varni JW, Yeatts K, DeWalt DA. Cognitive interviewing methodology in the development of a pediatric item bank: A patient reported outcomes measurement information system (PROMIS) study. Health Qual Life Outcomes. 2009;7:3.
- Morgan DeWitt E, Stucky BD, Thissen D, et al. Construction of the eight-item patient-reported outcomes measurement information system pediatric physical function scales: Built using item response theory. J Clin Epidemiol. 2011;64:794-804.
- Spiegel BMR, Khanna D, Bolus R, Agarwal N, Khanna P, Chang L. Understanding gastrointestinal distress: A framework for clinical practice. Am J Gastroenterol. 2011;106:380-385.
Impact of PROMIS on Clinical Practice
The potential impact of the PROMIS research on clinical practice should be significant, according to Dr. Morgan DeWitt, who says that both the ease of electronic administration and the brevity of the instruments are two major advantages. Currently at her hospital, quality-of-life measures are not always reliably administered. Because they are paper based, they are often not available when the physician sees the patient in his or her office.
