Osteoporosis Assessment Questionnaire-Physical Function (OPAQ-PF): a psychometrically validated osteoporosis-targeted patient reported outcome measure of daily activities of physical function

The purpose of this study was to evaluate the measurement properties of the Osteoporosis Assessment Questionnaire-Physical Functioning (OPAQ-PF). Based on this study, the OPAQ-PF has confirmed unidimensionality and acceptable reliability, construct validity, and sensitivity to change in a recent fracture/no recent fracture osteoporosis sample.

METHODS

Dimensionality was established through exploratory and confirmatory factor analysis. Patients completed three patient reported outcome (PRO) measures and four performance-based measures (PBMs) at baseline to enable an evaluation of construct validity. Patients without a recent fracture completed the OPAQ-PF 2 weeks after baseline to enable an evaluation of test-retest reliability. Ability to detect change and interpretation of change were investigated following completion of the OPAQ-PF 12 and 24 weeks postbaseline by patients with a recent fracture.

RESULTS

A prospective psychometric validation study in 144 postmenopausal women, with moderate to severe osteoporosis, 37 of whom had experienced a recent fragility fracture (<6 weeks). Unidimensionality was established for the OPAQ-PF by factor analysis. The OPAQ-PF had good internal consistency (α = 0.974) and test-retest reliability (mean intraclass correlation coefficient (ICC) 0.993. The OPAQ-PF differentiated between patients with/without recent fracture, and by severity of osteoarthritis; it correlated strongly with hypothesized-related scales and PBMs (r > 0.3, p < 0.001). Ability to detect change was established with high correlations between changes in OPAQ-PF score and changes in global concept scores in recent fracture patients (r ≥ 0.6, 24-week change). Effect size of change on OPAQ-PF score increased by level of global change (p < 0.001). Anchor-based methods identified an OPAQ-PF change of 10 at an individual patient level and 20 at a group level as meaningful to patients.

CONCLUSIONS

The OPAQ-PF has confirmed unidimensionality and acceptable reliability, construct validity, and sensitivity to change in a recent fracture/no recent fracture osteoporosis sample.

A discrete choice experiment to determine patient preferences for injection devices in multiple sclerosis

OBJECTIVE

Relapsing-remitting multiple sclerosis (MS) is usually managed with disease modifying drugs (DMDs), most commonly administered via self-injection. The aim of this study was to estimate the influence that different treatment-related attributes have for MS patients on their choice of MS DMD device. By establishing the relative importance of these characteristics for patients it should be possible to better understand the acceptability of a given device and to optimize the development of future devices.

METHODS

A discrete choice experiment (DCE) survey was developed on the basis of a review of published literature. Attributes identified for inclusion in the survey were: ease of use; comfort of use; presence of additional functions, needle visibility; practicality and efficacy. Choice sets were presented as pairs of hypothetical treatments based upon a fractional factorial design. One-hundred device-using MS patients completed the survey online. Analysis was conducted using a mixed-logit approach.

RESULTS

Analysis of the DCE data revealed that all attributes significantly predicted treatment choice. Efficacy exhibited the largest effect on treatment selection and this provided context for understanding the magnitude of impact for the other attributes. Reducing the discomfort associated with device use and eliminating the necessity for assembly or drug reconstitution were highly valued. The addition of reminder and time-stamping functions, improved needlestick injury prevention, and reduction in device size were secondary concerns but still deemed desirable.

CONCLUSION

Efficacy is of primary importance to MS patients, but characteristics of drug delivery devices can play an important role in treatment decision-making. Not all device characteristics could be included, and results are based upon 100 participants only. Findings suggest there is significant potential value in developing self-injection devices that are not only efficacious but also convenient and comfortable to use. Reducing barriers to adherence could potentially translate into improved treatment outcomes for patients with MS.

Utilities for advanced basal cell carcinoma

OBJECTIVE

Most incidences of basal cell carcinoma are cured by a number of surgical or non-surgical treatments. However, a few patients have lesions which have metastasized or progressed to an extent that surgery or other treatment options are not possible. The lesions associated with advanced basal cell carcinoma (aBCC) can be disfiguring, affecting patients' psychological state, general quality-of-life (QoL), and potentially life expectancy. The objective of this study was to capture societal utility values for health states related to aBCC, using the time trade-off (TTO) methodology.

METHODS

Nine health states were developed with input from expert clinicians and literature. States included: complete response (CR), post-surgical, partial response (PR) (with differing sized lesions [2 or 6 cm]), stable disease (SD) (with differing size and number of lesions [2 or 6 cm, or multiple 2 cm]) and progressive disease (PD) (with differing sized lesions [2 or 6 cm]). A representative sample of 100 members of the UK general public participated in the valuation exercise. The TTO method was used to derive utility values based upon subjects' responses to decision scenarios; between living in the health state for 10 years or living in a state of full health for 10-x years.

RESULTS

Mean utility scores were calculated for each state. The least burdensome state as valued by subjects was CR (mean = 0.94; SD = 0.08), suggesting only a minimal impact on QoL. The state valued as having a greatest impact on QoL was PD, with a 6 cm lesion (mean = 0.67, SD = 0.25).

LIMITATIONS AND CONCLUSIONS

Not all possible presentations of aBCC were included; the disease is a challenging condition to characterise given its rarity, the nature of the patients affected, and its variable progression. Findings suggest that aBCC is associated with significant burden for individuals, even when their disease is stable or where surgical treatment has been successful.