Development of an Exercise-Specific Parkinson's Disease Questionnaire: The PDQ-Exercise

BACKGROUND

Exercise is now a significant and key component in the management of Parkinson's disease. However, no self-report, Parkinson's-specific measure of exercise currently exists.

OBJECTIVE

To develop a patient-reported outcome measure (PROM) for use in studies and clinical trials that aim to assess the efficacy of exercise therapy for people with Parkinson's (PwP).

METHODS

Participants were recruited via Parkinson's UK. To generate meaningful items, PwP participated in exploratory cognitive interviews. To pretest the items generated, PwP took part in two rounds of cognitive debrief interviews. Items were subsequently tested through an online survey that also included the eight-item Parkinson's Disease Questionnaire (PDQ-8) and Oxford Participation and Activities Questionnaire (Ox-PAQ).

RESULTS

Twenty PwP were interviewed for item generation. Analyses identified issues related to adopting and maintaining exercise, resulting in the generation of 10 items. Fourteen PwP took part in subsequent cognitive debrief interviews. Following the first 10 interviews, one item was removed, and minor adjustments were made to the wording of two items. Four final interviews verified that no further adjustments were required. Consequently, nine items were included in the validation survey, which was fully completed by 398 PwP. Inspection of floor and ceiling effects resulted in the removal of two further items. A principal component analysis identified a single seven-item factor explaining 61.6% of variance. Further analyses indicated that the measure demonstrates sound reliability and validity.

CONCLUSIONS

Results indicate that the PDQ-Exercise is an acceptable, reliable, and valid PROM. Further assessment of its psychometric properties is in progress. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Oxford Participation and Activities Questionnaire (Ox-PAQ): development of a short form and index measure

Background

The Oxford Participation and Activities Questionnaire (Ox-PAQ) is a 23-item patient-reported outcome measure (PROM) theoretically grounded in the World Health Organisation International Classification of Functioning, Disability and Health. Initial validation of the Ox-PAQ identified three domains; routine activities (14 items), emotional well-being (5 items) and social engagement (4 items). The purpose of the analyses reported here were to determine whether an overall index score can be calculated from the measure, and then to determine whether a shorter form measure can replicate results on the index score.

Methods

Two surveys of people with long term conditions were undertaken. In the first study, higher order factor analysis is used to determine that a single index score can be calculated for the Ox-PAQ. Regression analyses are used to determine a sub-set of items selected for the Short Form Ox-PAQ (SF-Ox-PAQ). In the second study, results on the Ox-PAQ Single Index and SF-Ox-PAQ Single Index are compared with results from another generic measure, the EuroQol EQ-5D-5l.

Results

Higher order factor analysis confirmed that a single index score can be created from the Ox-PAQ. Further, linear regression indicated 14 items could reliably and accurately produce this index. The two methods of creating the index were highly correlated (ICC =0.99). The two indices were found to provide almost identical levels of correlation with EQ-5D-5L scores.

Conclusion

Results indicate that the Ox-PAQ can be summed to provide an index score, and, furthermore, a sub set of fourteen items can very closely replicate the results gained from the original parent form.

Measuring improvement in health-status with the Oxford Participation and Activities Questionnaire (Ox-PAQ)

Background: The Oxford Participation and Activities Questionnaire (Ox-PAQ) is a recently validated 23-item generic patient reported outcome measure that is theoretically grounded in the World Health Organisation International Classification of Functioning, Disability and Health (ICF), as well as fully FDA compliant. The measure comprises three domains, Routine Activities (14 items), Emotional Well-Being (5 items) and Social Engagement (4 items), and has been shown to be both valid and reliable. The aim of this study was to make a preliminary assessment of the sensitivity to the change of the Ox-PAQ.

Methods: Three hundred and seventy three people with either chronic pulmonary obstructive disease, motor neurone disease, multiple sclerosis or Parkinson’s disease completed the Ox-PAQ electronically on two occasions, six months apart. Participants completed an additional four questions during the second administration of the Ox-PAQ in order to assess any relevant changes since baseline. For each of the three Ox-PAQ domains, the minimally important difference (MID) and effect size (ES) was calculated from those participants indicating small, but meaningful positive improvement.

Results: Two hundred and ninety respondents were entered into the final analysis, 77.74% of the original sample. For those indicating “slight improvement” in Routine Activities (n=19), an MID of 7.51 and an ES of 0.32 was calculated. For Emotional Well-Being (n=26), the MID was 10.77 and the ES 0.44. For Social Engagement (n=16), the MID was 5.47 and the ES 0.28.

Conclusion: Data presented provides MID improvement and effect sizes for Ox-PAQ domains that will act as preliminary guidance for those powering clinical trials assessing activity and participation. Future research with larger samples will provide further sensitivity to change data for the Ox-PAQ.

Administering the Routine Activities domain of the Oxford Participation and Activities Questionnaire as a stand-alone scale: the Oxford Routine Activities Measure

Background

The recently validated Oxford Participation and Activities Questionnaire (Ox-PAQ) is a 23-item patient-reported outcome measure, theoretically grounded in the World Health Organization International Classification of Functioning, Disability and Health. The measure is specifically designed to assess participation and activity in people experiencing a range of health conditions. Initial validation of the Ox-PAQ identified three domains: Routine Activities (14 items), Emotional Well-Being (5 items), and Social Engagement (4 items). The purpose of the analysis reported here was to assess whether the Routine Activities domain of Ox-PAQ could be validated for use as a stand-alone measure without compromising its psychometric integrity.

Methods

Three hundred and seventy-three patients with a diagnosis of either chronic obstructive pulmonary disease, multiple sclerosis, or Parkinson’s disease were administered the Ox-PAQ in an online survey. The 14 items of the Routine Activities domain of the Ox-PAQ were subject to factor analytic techniques and assessed for reliability and validity.

Results

Three hundred and forty-one patients fully completed the survey, a completion rate of 91.4%. The 14 items loaded onto one single factor with an eigenvalue of 9.29 explaining 66.35% of variance. Reliability was confirmed through corrected item-total correlations ranging from 0.880 to 0.594 and a Cronbach’s alpha value of 0.96. Validity was demonstrated through significant differences in scores between the three disease groups assessed.

Conclusion

Results indicate that the Ox-PAQ Routine Activities domain can be legitimately adopted as a stand-alone measure, the Oxford Routine Activities Measure, where researchers wish to focus primarily on the activity component of the Ox-PAQ. It should, however, be emphasized that where a full assessment of all areas of activity and participation highlighted as important during the development of the Ox-PAQ is required, all three domains of the full measure should be administered.

Predictors of activity and participation across neurodegenerative conditions: a comparison of people with motor neurone disease, multiple sclerosis and Parkinson's disease

Background

Comparisons between neurological conditions have the potential to inform service providers by identifying particular areas of difficulty experienced by affected individuals. This study aimed to identify predictors of activity and participation in people with motor neurone disease (MND), people with multiple sclerosis (MS) and people with Parkinson’s Disease (PD).

Methods

The Oxford Participation and Activities Questionnaire (Ox-PAQ) and Medical Outcomes Study 36-Item Short Form Survey (MOS SF-36) were administered by postal survey to 386 people with a confirmed diagnosis of MND, MS or PD. Data analyses focused on stepwise regression analyses in order to identify predictors of activity and participation in the three conditions assessed.

Results

Three hundred and thirty four participants completed the survey, a response rate of 86.5%. Regression analyses identified multiple predictors of activity and participation dependent on Ox-PAQ domain and disease group, the most prominent being social and physical functioning as measured by the MOS SF-36.

Conclusions

Results indicate that the physical and social consequences of neurological illness are of greatest relevance to people experiencing the conditions assessed. Whilst the largely inevitable physical implications of disease take hold, emphasis should be placed on the avoidance of social withdrawal and isolation, and the maintenance of social engagement should become a significant priority.

Validation of the Oxford Participation and Activities Questionnaire

PURPOSE

There is growing interest in the management of long-term conditions and in keeping people active and participating in the community. Testing the effectiveness of interventions that aim to affect activities and participation can be challenging without a well-developed, valid, and reliable instrument. This study therefore aims to develop a patient-reported outcome measure, the Oxford Participation and Activities Questionnaire (Ox-PAQ), which is theoretically grounded in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF) and fully compliant with current best practice guidelines.

METHODS

Questionnaire items generated from patient interviews and based on the nine chapters of the ICF were administered by postal survey to 386 people with three neurological conditions: motor neuron disease, multiple sclerosis, and Parkinson's disease. Participants also completed the Medical Outcomes Study (MOS) 36-Item Short Form Health Survey (SF-36) and EQ-5D-5L.

RESULTS

Thus, 334 participants completed the survey, a response rate of 86.5%. Factor analysis techniques identified three Ox-PAQ domains, consisting of 23 items, accounting for 72.8% of variance. Internal reliability for the three domains was high (Cronbach's α: 0.81-0.96), as was test-retest reliability (intraclass correlation: 0.83-0.92). Concurrent validity was demonstrated through highly significant relationships with relevant domains of the MOS SF-36 and the EQ- 5D-5L. Assessment of known-groups validity identified significant differences in Ox-PAQ scores among the three conditions included in the survey.

CONCLUSION

Results suggest that the Ox-PAQ is a valid and reliable measure of participation and activity. The measure will now be validated in a range of further conditions, and additional properties, such as responsiveness, will also be assessed in the next phase of the instrument's development.

Development of the Oxford Participation and Activities Questionnaire: constructing an item pool

PURPOSE

The Oxford Participation and Activities Questionnaire is a patient-reported outcome measure in development that is grounded on the World Health Organization International Classification of Functioning, Disability, and Health (ICF). The study reported here aimed to inform and generate an item pool for the new measure, which is specifically designed for the assessment of participation and activity in patients experiencing a range of health conditions.

METHODS

Items were informed through in-depth interviews conducted with 37 participants spanning a range of conditions. Interviews aimed to identify how their condition impacted their ability to participate in meaningful activities. Conditions included arthritis, cancer, chronic back pain, diabetes, motor neuron disease, multiple sclerosis, Parkinson's disease, and spinal cord injury. Transcripts were analyzed using the framework method. Statements relating to ICF themes were recast as questionnaire items and shown for review to an expert panel. Cognitive debrief interviews (n=13) were used to assess items for face and content validity.

RESULTS

ICF themes relevant to activities and participation in everyday life were explored, and a total of 222 items formed the initial item pool. This item pool was refined by the research team and 28 generic items were mapped onto all nine chapters of the ICF construct, detailing activity and participation. Cognitive interviewing confirmed the questionnaire instructions, items, and response options were acceptable to participants.

CONCLUSION

Using a clear conceptual basis to inform item generation, 28 items have been identified as suitable to undergo further psychometric testing. A large-scale postal survey will follow in order to refine the instrument further and to assess its psychometric properties. The final instrument is intended for use in clinical trials and interventions targeted at maintaining or improving activity and participation.

Change in health status in long-term conditions over a one year period: a cohort survey using patient-reported outcome measures

Background

Enhancing quality of life for people with long-term conditions by monitoring patient-reported outcome measure scores is a key domain of health care policy. This study investigated the responsiveness of patient-reported outcome measures for long-term conditions.

Methods

A cohort survey was conducted in 33 primary care practices and 4485 patients (1334 asthma, 567 chronic obstructive pulmonary disease, 1121 diabetes, 525 epilepsy, 520 heart failure and 418 stroke) were sent a baseline survey containing a generic (EQ-5D) and a disease-specific measure. Baseline respondents were sent a follow-up after 1 year. Differences in scores for each long-term condition were assessed by paired t-tests. The relationship between scores and self-reported ‘change in health’ was assessed by analysis of variance.

Results

The baseline achieved a 38.4% response rate and the follow-up 71.5%. The only significant difference for the EQ-5D was found for the Visual Analogue Scale in heart failure between baseline and follow-up, and for change in health. Significant differences between baseline and follow-up scores were found on the disease-specific measures for 1 asthma dimension and 1 stroke dimension. No significant differences were found for other conditions. Significant differences between self-reported change in health and the disease-specific measures were found for 4 asthma dimensions and 2 stroke dimensions.

Conclusions

Few significant differences were found between the baseline and follow up or between ‘change in health’ and PROMs scores. This could be explained by the time frame of one year being too short for change to occur or by the PROMs not being responsive enough to change in a primary care sample. The latter is unlikely as the PROMs were in part chosen for their responsiveness to change. The baseline response rates may mean that the sample is not representative, and stable patients may have been more likely to participate. If PROMs are to be used routinely to monitor outcomes in LTCs, further research is needed to maximize response rates, to ensure that the PROMs used are reliable, valid and sensitive enough to detect change and that the time frame for data collection is appropriate.

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-014-0123-2) contains supplementary material, which is available to authorized users.

The Oxford Participation and Activities Questionnaire: study protocol

BACKGROUND

With an ageing population and increasing demands on health and social care services, there is growing importance attached to the management of long-term conditions, including maximizing the cost-effectiveness of treatments. In line with this, there is increasing emphasis on the need to keep people both active and participating in daily life. Consequently, it is essential that well developed and validated instruments that can meaningfully assess levels of participation and activity are widely available. Current measures, however, are largely focused on disability and rehabilitation, and there is no measure of activity or participation for generic use that fully meets the standards set by regulatory bodies such as the US Food and Drug Administration. Here we detail a protocol for the development and validation of a new patient-reported outcome measure (PROM) for assessment of participation and activity in people experiencing a variety of health conditions, ie, the Oxford Participation and Activities Questionnaire (Ox-PAQ). The stages incorporated in its development are entirely in line with current regulations and represent best practice in the development of PROMs.

METHODS

Development of the Ox-PAQ is theoretically grounded in the World Health Organization International Classification of Functioning, Disability, and Health. The project incorporates a new strategy of engaging with stakeholders from the outset in an attempt to identify those characteristics of PROMs considered most important to a range of potential users. Items will be generated through interviews with patients from a range of conditions. Pretesting of the instrument will be via cognitive interviews and focus groups. A postal survey will be conducted, with data subject to factor and Rasch analysis in order to identify appropriate dimensions and redundant items. Reliability will be assessed by Cronbach's alpha and item-total correlations. A second, large-scale postal survey will follow, with the Ox-PAQ being administered in conjunction with generic measures of health status to further test the validity of the measure. The Ox-PAQ will again be administered at 2 weeks to assess test-retest reliability and at 3 months to assess responsiveness.

CONCLUSION

The development of the Ox-PAQ is a timely one. With increasing emphasis being placed on the importance of keeping people active and participating in daily life, the instrument has the potential for significant uptake. Its primary use is intended to be in clinical trials and for evaluation of interventions targeted at maintaining activity and participation.

The Oxford Conception Study design and recruitment experience

The Oxford Conception Study is a randomised controlled trial that aims to determine whether or not information about potential fertility from a device that monitors urinary hormones will increase the conception rate in women wishing to conceive. Three modified versions of a fertility monitor have been developed for the study. The monitor measures the levels of urinary oestrone-3-glucuronide (E3G) and luteinising hormone (LH), and the display indicates high or low fertility. The monitor requests all women to test their urine from day 6 to day 25 of the menstrual cycle inclusive. One-third of women are randomised to receive information from the fertility monitor about the early fertile time (from the first rise in E3G until the LH surge is detected), one-third receive information about the late fertile time (the onset of the LH surge and the following 2 days), and a third do not receive any information (control group). All the women are followed up for 6 months or until they are pregnant. A total of 1453 women have been recruited into the study, reaching the study recruitment goal for 80% power to detect a 10% difference in three-cycle pregnancy rate between the Late Fertile Time group (50%) and the Control group (40%), allowing for a 15% non-pregnancy drop-out rate. Follow-up of the women is currently ongoing. The primary analysis will compare the cumulative three-cycle pregnancy rate between each of the study arms. Time-specific conception probabilities will be estimated from coitus information recorded in 12-h intervals. The data from this study will also allow many additional questions to be addressed, including changes in intercourse patterns with feedback about the fertile days and other questions in relation to menstrual cycle function, sexual intercourse, stress, exposures to tobacco products, alcohol, caffeine and medications, fertility and pregnancy outcomes. In addition to presenting the study design, we review the recruitment experience for the Oxford Conception Study. We have achieved sustained and effective recruitment over time by primary use of recruiting via the Internet.