Abstract
Patient-centred questionnaires and patient-reported outcome (PRO) measures are terms that are used interchangeably to reflect an instrument that provides evaluation of the lived experience of symptoms from the patients’ perspective. PRO use has grown significantly in the past 10–15 years, due to recognition of the importance of placing patients at the centre of their care [1]. It is recognised that only those individuals experiencing symptoms can report on the more subjective elements [2]. This is particularly important in the case of urodynamics, which is a clinical test. PROs provide a method of measuring subjective phenomena in an objective way and provide context to the data provided by clinical measurements. PROs can be used to record the presence and severity of symptoms and also to measure their impact, in particular on quality of life. This is useful when interpreting patients’ priorities for treatment and understanding the most bothersome aspect of their symptoms.
1.1 The History of the Development of Patient-Centred Questionnaire Assessment
Patient-centred questionnaires and patient-reported outcome (PRO) measures are terms that are used interchangeably to reflect an instrument that provides evaluation of the lived experience of symptoms from the patients’ perspective. PRO use has grown significantly in the past 10–15 years, due to recognition of the importance of placing patients at the centre of their care [1]. It is recognised that only those individuals experiencing symptoms can report on the more subjective elements [2]. This is particularly important in the case of urodynamics, which is a clinical test. PROs provide a method of measuring subjective phenomena in an objective way and provide context to the data provided by clinical measurements. PROs can be used to record the presence and severity of symptoms and also to measure their impact, in particular on quality of life. This is useful when interpreting patients’ priorities for treatment and understanding the most bothersome aspect of their symptoms.
PROs must be developed using a robust methodology in order to provide accurate measurements. It is therefore necessary to understand the principles underpinning their development in order to select the most appropriate questionnaires to use for a given patient, condition or clinical intervention [3]. The key characteristics to determine the robustness of a PRO are as follows (summarised in Table 1.1):
Context of use – the intended population.
Content validity – the process of item generation and interpretation of the PRO.
Psychometric robustness – characteristics of the measurement properties.
Table 1.1 PRO characteristics to evaluate measurement capability and robustness
| Parameter | Importance in PRO selection |
|---|---|
| Context of use | Determines appropriateness for the population in which use is intended |
| Content validity | Evidence of comprehensiveness and relevance to the population, and interpretation by potential respondents |
Psychometric robustness
| Quantitative data that provide evidence of measurement capability to provide robust and accurate data |
1.1.1 Context of Use
The PRO should be developed in a population that represents the intended respondents, to promote its applicability [4]. The developmental population may be specific and the appropriateness of the PRO for the intended population should be evaluated. Where the PRO appears to be relevant but has not been developed in the specific population, it can be further evaluated in the intended population for its relevance and appropriateness. The important factor is whether input has been sought from the intended population to derive the PRO content. Only by conducting qualitative research, for example, through interviews or focus groups, can the PRO be capture issues of relevance that are pertinent to potential respondents.
1.1.2 Content Validity
Content validity is an evaluation of whether the PRO captures what it intends to measure and whether it can be clearly interpreted to provide these data [2,5]. Cognitive debriefing interviews are typically employed to evaluate this in which potential respondents complete the draft PRO and discuss their thoughts while completing the tool, followed by a structured interview to assess whether question items are interpreted as intended [6].
1.1.3 Psychometric Robustness
1.1.3.1 Additional Validity
Other components of validity testing include:
Convergent validity – quantitative assessment of the relationship between findings from the PRO and measures of similar variables. Where constructs are closely related, the relationships should be stronger, and weaker relationships evident with more poorly related constructs.
Discriminant validity – an assessment of the PRO’s capability to distinguish between known patient groups, for example, those with mild, moderate, and severe symptoms.
Criterion validity – an assessment of the relationship between the PRO and an accepted gold standard, if available. Clinical proxy measures can be used as a direct comparison with a PRO, due to its variable nature is rarely possible.
These elements are typically considered essential for the complete validation of a PRO but should be judged in context. The more components of validity evaluated will provide more evidence of the robustness of the PRO to provide accurate and reliable data.
1.1.3.2 Reliability
The ability of the PRO to measure in a consistent manner over time is vital to ensure any change detected is due to a real change in symptom status, rather than measurement error. This can be measured in two ways:
1.1.3.3 Responsiveness
The PRO’s ability to detect change where real symptom improvement, or deterioration, has occurred is particularly important for outcome measurement in order to evaluate the change following intervention. The magnitude of change should also be evident in order to make comparisons between treatments with anticipated different effect sizes; for example, surgical versus conservative intervention [1].
1.2 The International Consultation on Incontinence Modular Questionnaire (ICIQ)
1.2.1 An ICIQ Overview
The International Consultation on Incontinence Modular Questionnaire (ICIQ) was developed to provide a universally applicable, standardised series of self-completion assessment instruments to evaluate lower urinary tract symptoms, lower bowel symptoms and vaginal symptoms [7]. It began in 1999 and now consists of a collection of 16 high-quality questionnaires including a validated bladder diary [8,9].
The ICIQ PROs can be used by men and women irrespective of age, with varied causes for their symptoms, facilitating the use of common questionnaires in many patient groups. It was developed from a standard protocol for the development and translation of ICIQ questionnaires. The content of the questionnaires is derived from patients and clinical experts, providing a robust evidence base for inclusion.
Core modules evaluate the core symptoms of lower pelvic dysfunction, namely lower urinary tract, lower bowel and vaginal symptoms. An example of an ICIQ module, the ICIQ-UI Short Form, is provided in Figure 1.1.
