Measurement and Tools Flashcards
Defining symptoms (complexities)
- Lack of consistent terminology
- Symptoms are inherently subjective (and as such patient-self report is the primary source of information)
- Patients may use different language and terms to define a sensation (e.g. shortness of breath may not mean ‘breathless’ for all patients)
- May be variation in the meaning of descriptors determined by culture, education, symptom experience, etc.
Measuring symptoms (complexities)
- Self-report is the ‘gold standard’
- There is poor correlation between observer and patient assessment
Measurable aspects of symptoms
- Frequency
- Severity
- Distress
Impact on other factors
- Other physical/psychological symptoms or diagnoses
- Function
- Family, social, financial, spiritual, and existential resources and concerns
Impact on global constructs
- Global symptom distress
- Health-related quality of life
Symptom measurement in routine clinical settings
- E.g. Edmonton Symptom Assessment Scale
- Standardized approach with a validated instrument can ensure consistent symptom assessment, detection, and documentation
- Ideally repeated at intervals
- May be a more global assessment (e.g. ESAS) or focussed on a single, high-impact symptom
- Some evidence for improved outcomes when routine symptom measures are augmented with a clinical pathway and expert consultation
Symptom measurement in clinical research
- Symptom checklists are not preferred, rather require validated measures that address more than one symptom dimension
- Standardised toxicity scales may be considered if symptom related outcomes are secondary endpoints
- QOL instruments often used, but were not developed as symptom assessment instruments and may not capture symptoms adequately or accurately
Methodological considerations for symptom measurement in clinical research
Patient-related factors
- Ability to provide consent and comprehend instruments (age, cognitive status, cultural/language barriers, patient’s particular descriptors, presence of other symptoms)
- Willingness to participate in data collection (may introduce bias)
Factors related to investigator goals and resources
- Study aims and methods (which symptoms, when should they be assessed, and what methodological controls are needed)
- Data management and statistical analysis (available resources for data collection and analysis)
Instrument-related factors
- Validity and reliability (for a symptom and for the particular population, ability to measure dimensions and impact of symptom)
- Statistical significance may not indicate a meaningful clinical difference - requires a ‘Minimal Important Difference’ in scores to indicate a clinical meaningfully changed
- Clinical utility and appropriateness (Capacity of instrument to assess the hypothesis, instrument complexity/burden to respondent)
Measurement of multiple symptoms: ESAS
Edmonton Symptom Assessment System
- Used extensively in PC research, validated
- Evaluates intensity of 9 common symptoms of cancer with a visual analogue scale (10th symptom can be added)
- Patient rating preferred, but there is experience with use of prodies
Measurement of multiple symptoms: Memorial Symptom Assessment Scale
- Validated, patient-rated measure of 26 symptoms (briefer version available with 15 symptoms)
- Translated in numerous languages, available in pediatric versions
- More valuable for research as a way to determine presence/absence of multiple symptoms and global symptom distress
Measurement of specific symptoms: Visual Analogue scale
- Most commonly used for dyspnea and pain
- Formats available for individuals with cognitive impairment
Measurement of specific symptoms: modified Borg scale
- Used to measure dyspnea (essentially scale of 0-10, 0 no breathlessness, 10 maximal breathlessness)
- Validated in health individuals and those with chronic pulmonary disease
- Change of 1 is minimally clinicaly important difference
Measurement of specific symptoms: Medical Research Council Dyspnea Scale
Medical Research Council Dyspnea Scale
- Assess consequences of breathlessness in relation to limitations on function
- Most useful when dyspnea is the only symptom experienced
- Not very sensitive in detecting subtle changes with an intervention
Measurement of specific symptoms: Cancer Dyspnea Scale
Cancer Dyspnea Scale
- Rates effort, anxiety, and discomfort severity on a 5 point Likert scale
- May capture interplay between anxiety and dyspnea
Measurement of Specific Symptoms: MMSE
Mini Mental Status Exam
- Tools are sensitive indicators of cognitive impairment, but not specific for the diagnosis of delirium
- Scoring may be influenced by culture and education levels
- Least useful for delirium, as per JAMA MMSE should not be used to screen for delirium, as it has the least useful LR of all studied instruments. (MMSE <24, LR+ 1.6)
Measurement of Specific Symptoms: Confusion Assessment Method
Confusion Assessment Method for delirium Requires both of: - Acute onset and fluctuating course - Inattention And one of: - Disorganized thinking - Altered LOC
Reasonable LRs for delirium:
- CAM positive (LR 7.3 by nurses, 19 by physicians)
Challenges to applying symptom measures in PC settings
Healthcare providers
- Scepticism about validity or importance of standardised measures
- Lack of familiarity
- Knowledge and skills
Tools
- Lack of validity in our patient population
Lack of standardization across geographic areas
- QI methods may be helpful to result in the more universal application of methods
Systems-issues
- Ease of use (e.g. with paper charts, etc.)
Patient barriers
- Patient difficulty completing measures (cognitive impairment, fatigue, etc.)
- Symptom distress may hinder ability to provide information
- Reluctance to answer sensitive questions
- Language barriers
