Recognising the lack of standardised measurement in the assessment of patient-reported outcomes, scientists from academic institutions and the NIH formed a cooperative group in 2004 to transform health measurement with the Patient-Reported Outcomes Measurement Information System (PROMIS). (Cella et al., 2007).

The PROMIS profile instruments are a collection of short forms containing a fixed number of items from seven PROMIS domains (depression, anxiety, physical function, pain interference, fatigue, sleep disturbance, and ability to participate in social roles and activities). There are three PROMIS Profile Forms: PROMIS-29, PROMIS-43, and PROMIS-57. The profiles are universal rather than disease-specific. They assess all domains over the past seven days except for Physical Function which has no timeframe specified (Huang et al., 2018).

The PROMIS-29 assesses each of the 7 domains with 4 questions with an additional pain intensity numeric rating scale (NRS) i.e. question 29 of the score. The PROMIS measures have been tested and validated in large reference populations making them suitable for research on different conditions (Health Measures).

The PROMIS-29 and its subdomains have been validated and/or cross-walked to a host of legacy measures in a variety of populations, including the Oswestry Disability Index, Roland-Morris Disability Questionnaire, Brief Pain Inventory-Pain Interference domain, the EuroQol Research Foundation five-dimension (EQ-5D) instrument, and quality-adjusted life-year calculations (Pope et al., 2020).

Evaluation of PROMIS-29

The patients’ answers to the PROMIS-29 are scored from 1-5 (with the exception of the NRS). The sum of the PROMIS results in the raw score, which lies between 4 and 20. There is no total score, but each axis forms its own score. PROMIS assessments use an Item Response Theory (IRT) based score called “Expected A Posteriori” or EAP scores, which are then transformed onto a final T-score metric. This means that the scores are mapped so that the values follow a normal distribution with a population mean T-score of 50 and a standard deviation of 10.

With the added characteristics of inclusivity (i.e., applicable to a wide array of patients) and comparability (i.e., measures are comparable across different patients and clinical circumstances), the PROMIS instruments have become attractive outcome measures in chiropractic research and clinical practice (Alcantara et al., 2018; Alacantara et al., 2021; Hays et al., 2019)


The PROMIS-29 is quickly becoming a standard for PRO research and practice and is recommended for initial outcome assessment (Adams et al., 2012). The PROMIS-29 measure has a greater range of measurement compared to most conventional measures thus decreasing floor and ceiling effects. Studies continue to support its construct validity and feasibility, in fact, one study stated that it may be superior to the SF-36 (Hinchliff et al., 2011; Craig et al., 2014).

The PROMIS-29 has a reduced responder burden, therefore continued patient engagement is higher due to the fewer items included. When used as computer adaptive tests (CAT), PROMIS measures generally require 4 – 6 items to achieve precise measurement of health-related constructs (Ryan 2021).

Pope et al., 2021 found that the PROMIS-29 showed great generalisability across a diverse cohort, with fairly homogeneous findings in a multi-center analysis of patients’ baseline pain quality upon entry to chronic pain centers in the US. Patients were examined in clinics across the United States spanning over 2 years, spanning previous treatments, medications, surgeries, and diagnoses.

The ability of the PROMIS-29 to fulfill the above criterion makes it an advantageous tool to thoroughly evaluate the patient quality of life coupled with ease of use.


In a study investigation into the variation and change over time in PROMIS-29 in primary care patients with type 2 diabetes mellitus, it was determined that whilst the use of PROMs in routine clinical care identified areas of functional limitations among the patients, changes in participants’ PROMIS-29 scores over time were minimal. The paper highlighted that additional research is needed to understand the patterns of change in global and domain-specific functioning, particularly among racial/ethnic minorities (Homco et al., 2019).

Comparing against different scores

The PROMIS-29 v2.0 physical and mental health summary scores have clear advantages over existing summary scores. Firstly, the PROMIS v2.0 summary health measures are more reliable than the PROMIS global health summary scores from studies by Hays et al., 2018.

Secondly, the new summary scores were constructed allowing physical and mental health to be correlated rather than forcing a zero correlation between them as was the case for the SF-36 summary scores (Farvair et al., 2007)

Alcantara et al., 2021 concluded that the PROMIS-29 and PROMIS Global Health scores were more appropriate instruments for assessing the quality of life with the ultimate purpose of assessing overall mental, physical and social health in comparison to the SF-36 from chiropractic patient responders.


According to the provider, licensing fees are subject to negotiation but fees are estimated to be 250 euros per year, per department.


The PROMIS initiative has advanced the science of PRO measurement through instrument development using both qualitative and quantitative methods and application of modern. The bigger achievement of PROMIS is that it creates a framework of health that is indispensable for standardization. Overall, PROMIS aims to ensure that existing and future tools are standardized to provide data that can be widely interpreted, trusted, and compared to derive actionable results. The PROMIS-29 has been used in thousands of studies, published in over 150 journals, and is validated with cross-talks to other instruments (Pope et al., 2021).