It is not considered uncommon for there to be some statistical anomalies during data analysis. Some of the more frequently seen in HRQoL analysis are the ceiling effect, the floor effect, and response shift bias.
The ceiling effect refers to how patients who start with a higher quality of life than the average patient do not have much room for improvement when treated. The opposite of this is the floor effect, which refers to patients who have a lower quality of life average have much more room for improvement. Consequentially, if the spectrum of quality of life before treatment is too unbalanced, there is a greater potential for skewing the end results, creating possibility for incorrectly portraying a treatment's effectiveness or lack thereof.
Response Shift Bias
Response shift bias is an increasing problem within longitudinal studies that rely on patient reported outcomes. It refers to the potential of a subject’s views, values, or expectations changing over the course of a study, thereby adding an additional factor of change on the end results. Clinicians and healthcare providers must recalibrate surveys over the course of a study to account for Response Shift Bias. The degree of recalibration varies due to factors based on the individual area of investigation and length of study.
Frequently Used HRQoL Measures
Here are some examples of frequently used HRQoL questionnaires:
The ceiling effect refers to how patients who start with a higher quality of life than the average patient do not have much room for improvement when treated. The opposite of this is the floor effect, which refers to patients who have a lower quality of life average have much more room for improvement. Consequentially, if the spectrum of quality of life before treatment is too unbalanced, there is a greater potential for skewing the end results, creating possibility for incorrectly portraying a treatment's effectiveness or lack thereof.
Response Shift Bias
Response shift bias is an increasing problem within longitudinal studies that rely on patient reported outcomes. It refers to the potential of a subject’s views, values, or expectations changing over the course of a study, thereby adding an additional factor of change on the end results. Clinicians and healthcare providers must recalibrate surveys over the course of a study to account for Response Shift Bias. The degree of recalibration varies due to factors based on the individual area of investigation and length of study.
Frequently Used HRQoL Measures
Here are some examples of frequently used HRQoL questionnaires:
- Healthy Day Measures: A questionnaire with four base questions and ten optional questions used by the Center for Disease Control and Prevention (CDC).
- Short-Form Health Survey: One example of a widely used questionnaire assessing physical, social, and mental HRQoL, used in clinical trials. Suitable for pharmacoeconomic analysis, benefiting healthcare rationing.
- Manchester Short Assessment of Quality of Life: 16-item questionnaire for use in psychiatric populations.
- EQ-5D a simple quality of life questionnaire.
- WHO-Quality of life BREF: A general Quality of life survey validated for several countries.