Advances in treating and detecting chronic and rare diseases are improving the life expectancies of individuals with sickle cell disease (SCD) in many ways. For up to 90,000 individuals that are born with the sickle cell disease in the US, infant screening, improved therapies, and better management of the rare blood disorder have all improved the lives of such people in unprecedented ways. Presently, more than 95% of the people born with this condition grow into adulthood on account of the increase in the use of preventive medicine and other therapy related advances.
With the improved management of the disease, questions now arise on the experience and impact of the disease across the lifespan of an individual. Their well-being and optimal functioning are affected by the condition on account of the pain, multi-organ failure, and the neurocognitive deficits encountered as they age. The economic and social challenges encountered have also not been properly investigated as well as the barriers such individuals experience in accessing quality health care. There was, therefore, the need to have a better understanding of the long-term requirements of adults with this condition for health care providers to be in a position to offer skilled adult-oriented heath care.
The National Heart, Lung and Blood Institute (NHLBI) organized workshops and conferences in 2002 for stakeholders to suggest new ways of improving the treatment given to adults with SCD (Treadwell, 2014). The stakeholders suggested the need for a valid, reliable, and systematic method for recording the adult patient-reported outcomes. The NHLBI contracted the Children’s Hospital & Research Center Oakland to come up with a sickle cell disease quality of life quantification system that would address the gaps in understanding the long-term needs and experiences of patients. This collaboration led to the development of the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me), it was designed to address the information gap related to the management of this disease in this population. ASCQ-Me pronounced as “Ask Me” is a Patient-Reported Outcome system that targets adults with SCD and help document their perspective.
Easy to use
Development of ASCQ-Me began with a literature review that meant to establish the important health-related quality of life (HRQOL) issues to be assessed. Detailed and structured interviews were conducted to determine the life areas that affect people with SCD. The interviews were conducted by SCD experts on adults with the disease who varied in gender, age and location. The research identified the important measures that assess the severity of one’s disease, the mental, physical and social health aspects (emotional distress, functioning in the family, sexual, and work-related roles) and the overall quality of life and health care received.
The formative research led to the identification of the following areas as being of concern in the administration of SCD related treatment.
- Unnecessary delays in healthcare settings, especially the Emergency Department.
- Some health care providers do not consider the information provided by the SCD patients when writing the prescriptions; this has in some instances lead to overmedication for pain and other symptoms.
- Lack of knowledge in SCD related complications by health care providers in the emergency department and the providers of primary care. This has often led to the vilification of the SCD patients as being drug seekers, and it results in ineffective and inappropriate care.
The data collected was analyzed at the item level and bank level to confirm the factor structure of the domains. Item response theory (IRT) and classical test theory techniques were used in the analysis that led to the development of the final measures.
Consumer Assessments of Healthcare Providers and Systems (CAHPS) is the most widely used method of reporting and capturing patients’ approval and experiences with their healthcare providers. This format was used in the design of the ASCQ-Me measures in line with the results of the interviews conducted on SCD patients. CAHPS measures are used widely to evaluate the performance of Medicaid, Medicare, hospitals, dialysis facilities, private health plans, etc. CAHPS are used by the Department of Veterans Affairs, the Department of Defense, and the Center for Medicare and Medicaid Services (CMS) to evaluate the kind of care that their beneficiaries receive.The ASCQ- Me measures were based on the framework of how the disease affects adults. The development of the measures in ASCQ –Me employed a wide range of quantitative and qualitative research methods. They employed the same research methods as those that were used in coming up with the PROMIS. Computer Adaptive Tests (CATs) and IRT models were used in the development of the measures, as was the case was in the development of the PROMIS. The models are used to come up with standardized patient-reported outcomes while at the same reducing the burden on the respondents.
ASCQ-Me employs three types of instruments; short forms, computer adaptive tests and a Sickle Cell Disease Medical History Checklist (SCD-MHC). The measures seek to assess the emotional, social and physical impact of the disease through self-report. The short forms contain a set of 5 questions that cover a specific domain while the checklist contains a given set of items that are used descriptively. Scoring on the checklist is not based on item response theory. In the CATs, the tests are administered from an item bank depending on the previous answers by the respondent. 4-12 items are commonly administered with a very high level of precision.Under the physical impact of the disease, the impact of the pain, the frequency of the pain episodes, lack of sleep, and stiffness are assessed. The domains covered by ASCQ-Me includes the pain impact, pain episode, stiffness impact, sleep impact, emotional impact, social functioning impact, and the sickle-cell disease medical history checklist.
The pain impact item bank measures the severity of the pain and the impact it has on the person’s ability to perform their daily duties. Higher scores indicate less pain, better pain control, and less impact on the normal functioning of the individual. This measure seeks to assess the severity of the pain and does not concern itself with the quality of pain or the behavior associated with the pain.
The pain episode domain encompasses severity and frequency of pain. Higher scores indicate increased severity and frequency of the pain episodes. This measure does not focus on the unpredictability of pain episodes but rather seeks to assess how the pain episodes due to SCD affect such individuals.
The stiffness impact item bank measures the level of stiffness that may affect the movements of the patient and its severity. The higher the scores, the lesser the impact and severity of stiffness on the individual’s life.
The sleep impact item bank measures the impact SCD has on the ability of the individual to fall asleep, stay asleep, getting enough sleep, and falling back asleep after waking up. Higher scores mean SCD has less effect on the sleeping patterns of the individual and better sleep eventually.
The emotional impact measures the impact of SCD on the individual’s emotions and feelings. The emotional impact assesses feelings of loneliness, depression, and worry. Higher scores indicate less emotional distress and less impact on the person’s normal functioning. The emotional impact measures require the patient to characterize the frequency and severity of his or her emotional state in the context of how SCD impacts how they feel.
The social functioning impact item bank measures the impact of the disease on activities with friends and family. Questions in this item bank do not ask about the ability to perform social roles of a friend, parent, worker, spouse or for a member of the community. Higher scores indicate less impact of the disease on social functioning.
The Sickle-cell disease medical history checklist (SCD-MHC) is not designed to assess changes in the wellbeing and health of individuals with SCD over time. It is rather intended to describe the severity of the disease in an individual. Questions in the checklist ask the individuals to report any bone damage, organ damage, and other symptoms that are associated with SCD. Scores in the checklist are normally the same with very small changes in the short term.
Modern psychometric theory and classical theory were both used to evaluate the ASCQ-Me measures. The confirmatory and exploratory analysis was used to examine the unidimensionality assumption of all the ASCQ-Me domains.The measures can be administered in two ways: As an electronic assessment or as a paper- and-pencil (PAP) assessment. The Computer Adaptive Tests (CATs) can only be administered through a computer. The PAP assessment consists of six different forms covering the different domains measured in ASCQ-Me (Stiffness Impact, Pain Impact, Emotional Impact, Pain Episodes, Sleep Impact and the Social Functioning Impact.) Each of these domains has five different questions that are normally administered to assess the impact, frequency or severity of the different measures. The SCD Medical History Checklist is also administered as a PAP. The electronic assessment is administered either adaptively, whereby each patient gets a different set of questions depending on their level of health or in a fixed format in which case every patient answers the same set of questions.ASCQ-Me measures are automatically scored and can be interpreted using an algorithm. The measures rely on a T-score metric in which 50 is the mean of the relevant reference, and 10 is the standard deviation of that population. So, 10 points in the scoring mean 1 standard deviation, where a score of 40 will be one standard deviation below the average score of the reference population, similarly a score of 70 will be two standard deviations higher than the average of the reference population. Pain episode and SCD-MHC’s high scores indicate worse health outcomes, whereas high scores for pain impact, sleep impact, emotional impact, stiffness impact, and social functioning impact indicate better health outcomes. The scores can be interpreted by these two trends i.e. the direction of scores, and the difference in scores between the score of the patient and the mean of the relevant reference (50).Some of the strengths of ASCQ-Me include:
- Individuals with SCD can use ASCQ-Me to record the impact of the disease on their day-to- day activities. In this way, they can track changes in their health over time and can discuss this with their healthcare provider.
- ASCQ-Me is also of great value to researchers as it can be used in clinical trials, during drug development, and to assess the outcomes of treatment in patients that are treated in different healthcare delivery units. ASCQ-Me also enables researchers to understand disparities in wellbeing and functioning across different groups of adults with SCQ in clinical, population and health services –based research.
- For health care providers, ASCQ-Me can be used in addition to other physiological measures of the severity of the disease. ASCQ-Me also points out other important aspects that can be missed by other physiological measures- these aspects include emotional distress, impact on the sleeping patterns, and normal functioning.
- Use of advanced psychometric methods in its development, in line with the PROMIS initiative standards.
- Careful attention to eliminating and evaluating bias in measurement.
- The development of item banks with short sets of questions on each aspect of health that can be administered adaptively or via fixed forms enabling precise measurements with few questions.
- ASCQ-Me measures have also been validated using a measure of SCD severity that is not affected by the weaknesses of the measures that are mostly used such as SCD type or the number of hospitalizations.
With the continued improvements in therapy, the life expectancy of individuals with SCD has continued to improve over the past several decades. SCD is now a condition that most people can manage into old age. We now have a better understanding of the acute treatment needs of individuals with SCD, but do not have information on the long-term needs of adults with this condition at the moment.
An accurate measure of health outcome is necessary to enable the delivery and design of quality health care to people with SCD. ASCQ-Me measures were developed using advanced psychometric methods such as those used in the development of the PROMIS initiative. In coming up with the ASCQ-Me measures of sleep, pain, cognitive, social, emotional and stiffness impact, a comprehensive program of statistical analysis and formative research of field test data on more than 550 people living with SCD was carried out.
Research on ACQ-Me is ongoing that seeks to:
- Come up with alternative administration platforms for ASCQ-Me.
- Integrate ASCQ-Me into SCD registries.
- Determine the ability of the ASCQ-Me scores to detect changes in the health of the patient over time.
- Define when to use PROMIS versus ASCQ-Me, and how and when to use the two in concert.
- Translate ASCQ-Me into other languages that are spoken in the US.
ASCQ-Me is already in use in a number of studies, and this will help understand the usefulness and the validity of the scores in the system. One of the features of the ASCQ-Me system that will be revealed in due time is the sensitivity of the scores to any changes in the health of the individual that may result from changes in how health care is delivered or from drug related therapies.Reeve, B., Hays, R. D., Bjorner, J., Cook, K., Crane, P. K., Teresi, J. A., Thissen, D., Revicki, D. A., Weiss, D. J., Hambleton, R. K., Liu, H., Gershon, R., Reise, S. P., Lai, J. S., Cella, D., & on behalf of the PROMIS cooperative group. (2007). Psychometric evaluation and calibration of health–related quality of life item banks: Plans for the Patient–Reported Outcome Measurement Information System (PROMIS). Medical Care, 45(5), S22–31.
Treadwell, M. J., Hassell, K., Levine, R., & Keller, S. (2014). Adult sickle cell quality-of-life measurement information system (ASCQ-Me): Conceptual model based on review of the literature and formative research. The Clinical Journal of Pain, 30(10), 902-914.
Keller S, Yang M, Treadwell MJ, Werner EM, Hassell K. (2014). Patient Reports of Health Outcome for Adults Living with Sickle Cell Disease: Development and Testing of ASCQ-Me Item Banks