by Dr Nicola Davies
It has been estimated that 1.8 million people in England are living with and beyond cancer, with a predicted annual increase in prevalence of three percent. Due to considerable advances in the effectiveness of new drugs and treatments for people with cancer, a new patient population with unique needs has emerged – cancer survivors. This article highlights the importance of utilising patient-reported outcome measures (PROMs) in the assessment of the needs of this patient population, and provides guidance on how to select the most reliable PROMs.
It has been estimated that 1.8 million people in England are living with and beyond cancer, with a predicted annual increase in prevalence of three percent. Due to considerable advances in the effectiveness of new drugs and treatments for people with cancer, a new patient population has emerged with unique needs – cancer survivors. Indeed, studies have shown a significant gap between the performance of healthcare providers and the needs and expectations of cancer survivors, many of whom are contending with the after effects of both the disease and it's invasive and sometimes traumatic treatment.
The needs of cancer survivors, like most people, includes maintaining health-related quality of life (QoL), which comprises various dimensions of well-being – social, mental, and physical. However, QoL is especially important for cancer survivors, where treatment trajectory can result in long-term sequelae with residual disability, depending on type of cancer, stage at diagnosis, and other factors. Not only do patients need to cope with the initial stress of their diagnosis, they must also face physically demanding (and often life-threatening) treatments for their illness, which can last months. These treatments may have significant physical, mental, and social impacts such as fatigue, financial stress, inability to perform activities of daily living, fear of death, and depression.
The increase in cancer survivors and people living with long-term conditions has necessitated acknowledgement of the fact that to truly meet the care needs of any patient population, the patient needs to have an active role in the care process. This, in turn, has sparked a major paradigm shift away from the traditional objective clinical patient measures of health and care needs assessment, towards the development of patient-reported outcome measures (PROMs) that offer a subjective insight into patient needs related to various domains of well-being.
PROMs come in many forms, each of which have been designed with a specific outcome in mind.
Generic PROMS can be used to examine issues that are applicable across a variety of health conditions and can be particularly useful in generating normative data and making comparisons that can assist in the development of new methods of care. There is an increasing need to standardise the use and interpretation of results in clinical trials across the globe, especially in cases of drug manufacturers who wish to introduce their products across regional boundaries such as those of the United States and Europe. The disadvantage of using generic PROMs is that they may not provide adequate focus on a prevailing condition. Furthermore, they may not be responsive to changes in treatment regimens. Cancer-specific PROMs, however, are useful in identifying specific symptoms related to a particular type of cancer and its impact on individuals. Many of these are available in physical formats as well as online modules (ePRO measures), which can ease distress and improve chemotherapy adherence, as discussed at this years ASCO conference.
It is often necessary to use both generic and disease-specific PROMs for a greater understanding of the effectiveness of interventions or the needs of an individual patient or patient group. However, what is perhaps more important than instrument type when selecting the most appropriate outcome measure is a consideration of the psychometric properties and operational characteristics of the instrument. Indeed, psychometrically reliable and operationally feasible PROMs can provide deep insights into the effectiveness and impact of various treatment regimens, as well as expose the level of symptom severity and the burden of the disease on the patient.
When selecting the most appropriate PROMs to use, there are specific appraisal criteria that can be used to facilitate decision-making. These criteria take into consideration the psychometric properties of the measure, such as reliability and validity as well as practical properties related to the measure, such as ease-of-use and acceptability. In the case of cancer, it is extremely important to evaluate and assess QoL and its various domains from when the condition is diagnosed in order to provide optimal care and support as interventions progress and patients enter survivorship.
There are several ongoing initiatives in Europe and the US that have been successful in developing PROMs that are increasingly used to refine clinical decision-making for cancer survivors. While the use of cancer-specific PROMs is becoming increasingly popular in clinical trials and research studies, they are yet to be integrated into the national health system as standard tools used for routine measurement of cancer burden. In England, however, the 2010 National Cancer Patient Experience Survey succeeded in providing health care organisations with greater insights into the strengths and weaknesses of prevailing cancer care, provision in the national health system, and the need to develop cancer-specific PROMs.
Studies have shown that a population-based survey approach can provide great insights into how interventions can be better developed to reduce the long-term impact of treatment on cancer survivors. The objective in a study by Glaser et al. (2013), for example, was to “determine the feasibility of collecting population-based PROMs in assessing QoL to inform the development of a national PROMs programme for cancer and to begin to describe outcomes in a UK cohort of survivors”. The results indicate that the population-based collection of PROMs is feasible and useful in developing a database of cancer-related morbidities, as well as for evaluating and assessing the QoL of cancer survivors with long-term conditions. Indeed, the Cancer Strategy for England now recommend pilot trials collecting QoL in all survivors, and for data to be recorded in their Cancer Dashboard.
Specific PROMs are necessary to gain a better understanding of how including particular drugs such as monoclonal antibody drugs into specific cancer regimens can affect the QoL of patients. Several clinical trials, including the one conducted by the Eastern Cooperative Oncology Group in the US, have returned positive results about the efficacy of the measures used. The objective in the study was to determine the effect on QoL when Doxorubicin (Adriamycin) and Cyclophosphamide (Cytoxan) was included in the treatment regimen of breast cancer patients.
The Functional Assessment of Cancer Therapy (FACT), the EQ-5D, and the Memorial Symptom Assessment Scale provided valid and reliable information about breast cancer patients’ QoL. An advantage of the FACT instrument is that it not only measures generic constructs of QoL, but clinicians can also select an additional subscale to make the measure specific to a cancer or treatment type. Another alternative measure would be the EORTC computerised adaptive testing (CAT) system, which features cancer-specific support of questionnaires.
In addition to implementing population-based measures of cancer survivorship, it is also recommended that national health services incorporate these PROMs into routine practice, selecting those most appropriate to their outcomes of interest. The Department of Health should take the initiative to standardise these measures so that results across the nation can be pooled for the purpose of developing the most effective interventions for cancer survivors.
It is clearly important to assess the needs of cancer survivors, whether in terms of their overall health (physical, social and emotional) or more specifically their psychological well-being. However, there is an extensive array of PROMS available to assist with QoL and psychological well-being assessments, which ultimately makes the task of selecting an appropriate measure challenging. This paper has provided guidance on the key considerations when selecting PROMs, with emphasis being placed on the psychometric and practical properties of such instruments. In addition, it is advised that while generic measures are necessary for population-based monitoring and routine assessments, it is fundamental to integrate condition- and dimension-specific instruments into such assessments when aiming to identify both individual needs and those needs unique to cancer survivors.