Evaluation of clinically relevant changes in patient reported outcomes in knee and hip osteoarthritis: the minimal clinically important improvement

Background: In clinical trials, at the group level, results are usually reported as mean and standard deviation of the change in score, which is not meaningful for most readers. Objective: To determine the minimal clinically important improvement (MCII) of pain, patient's global assessment of disease activity, and functional impairment in patients with knee and hip osteoarthritis (OA). Methods: A prospective multicentre 4 week cohort study involving 1362 outpatients with knee or hip OA was carried out. Data on assessment of pain and patient's global assessment, measured on visual analogue scales, and functional impairment, measured on the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) function subscale, were collected at baseline and final visits. Patients assessed their response to treatment on a five point Likert scale at the final visit. An anchoring method based on the patient's opinion was used. The MCII was estimated in a subgroup of 814 patients ( 603 with knee OA, 211 with hip OA). Results: For knee and hip OA, MCII for absolute ( and relative) changes were, respectively, ( a) -19.9 mm (-40.8%) and -15.3 mm (-32.0%) for pain; ( b) -18.3 mm ( - 39.0%) and -15.2 mm ( -32.6%) for patient's global assessment; ( c) -9.1 ( -26.0%) and -7.9 ( -21.1%) for WOMAC function subscale score. The MCII is affected by the initial degree of severity of the symptoms but not by age, disease duration, or sex. Conclusion: Using criteria such as MCII in clinical trials would provide meaningful information which would help in interpreting the results by expressing them as a proportion of improved patients.

Evaluation of clinically relevant states in patient reported outcomes in knee and hip osteoarthritis: the patient acceptable symptom state

Background: The patient acceptable symptom state ( PASS) is the value beyond which patients can consider themselves well. This concept can help in interpreting results of clinical trials. Objective: To determine the PASS estimate for patients with knee and hip osteoarthritis (OA) by assessing pain, patient's global assessment of disease activity, and functional impairment. Methods: A 4 week prospective multicentre cohort study of 1362 outpatients with knee or hip OA was carried out. Data on assessment of pain and patient's global assessment of disease, measured on visual analogue scales, and functional impairment, measured on the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) function subscale, were collected at baseline and final visits. The patients assessed their satisfaction with their current state at the final visit. An anchoring method based on the patient's opinion was used. Results: For patients with knee and hip OA, the estimates of PASS were, respectively, 32.3 and 35.0 mm for pain, 32.0 and 34.6 mm for patient global assessment of disease activity, and 31.0 and 34.4 points for WOMAC function score. The PASS varied moderately across the tertiles of baseline scores but not across age, disease duration, or sex. Conclusion: The use of PASS in clinical trials would provide more meaningful results expressed as a proportion of patients in an acceptable symptom state.

Evaluation of WOMAC 20, 50, 70 response criteria in patients treated with hylan G-F 20 for knee osteoarthritis

Objective: A secondary analysis of a previously conducted one year randomised controlled trial to evaluate the capacity of responder criteria based on the WOMAC index to detect between treatment group differences. Methods: 255 patients with knee osteoarthritis were randomised to appropriate care with hylan G-F 20'' (AC+H) or appropriate care without hylan G-F 20'' (AC). In the original analysis, two definitions of patient response from baseline to month 12 were used: ( 1) at least a 20% reduction in WOMAC pain score ( WOMAC 20P); ( 2) at least a 20% reduction in WOMAC pain score and at least a 20% reduction in either WOMAC function or stiffness score ( WOMAC 20PFS). For this analysis, a responder was identified using 50% and 70% minimum clinically important response levels to investigate how increasing response affects the ability to detect treatment group differences. Results: The hylan G- F 20 group had numerically more responders using all patient responder criteria. Increasing the response level from 20% to 50% detected similar differences between treatment groups (25% to 29%). Increasing the response level to 70% reduced the differences between treatment groups (11% to 12%) to a point where the differences were not significant after Bonferroni adjustment. Conclusions: These results provide evidence for incorporating response levels ( WOMAC 50) in clinical trials. While differences at the highest threshold ( WOMAC 70) were not statistically detectable, an appropriately powered study may be capable of detecting differences even at this very high level of improvement.

An evaluation of a telephone-based postnatal support intervention for infant feeding in a regional Australian city

Background: Postnatal breastfeeding support in the form of home visits is difficult to accommodate in regional Australia, where hospitals often deal with harsh economic constraints in a context where they are required to provide services to geographically, dispersed consumers. This study evaluated a predominately telephone-based support service called the Infant Feeding Support Service. Methods: A prospective cohort design was used to compare data for 696 women giving birth in two regional hospitals (one public, one private) and participating in the support service between January and July 2003 with data from a cohort of 625 women who gave birth in those hospitals before the introduction of the support service. Each mother participating in the support service was assigned a lactation consultant. First contact occurred 48 hours after discharge, and approximately it weekly thereafter for 4 it weeks. Breastfeeding duration was measured at 3 months postpartum. Results: For women from the private hospital, the support service improved exclusive breastfeeding duration to 4.5 weeks postpartum, but these improvements were not evident at 3 months postpartum. No effects were observed for mothers from the public hospital. Quantitative and qualitative data demonstrated high levels of client satisfaction with the support service. Conclusions: This small-scale, predominately telephone-based intervention provided significant, although apparently context-sensitive, improvements to exclusive breastfeeding duration.

Evaluation of candidate markers for the peritubular myoid cell lineage in the developing mouse testis

Despite the importance of peritubular myoid (PM) cells in the histogenesis of the fetal testis, understanding the origin and function of these cells has been hampered by the lack of suitable markers. The current study was aimed at identifying molecular markers for PM cells during the early stages of testis development in the mouse embryo. Expression of candidate marker genes was tested by section in situ hybridisation, in some instances followed by immunofluorescent detection of protein products. Collagen type-1, inhibin beta A, caldesmon 1 and tropomyosin 1 were found to be expressed by early-stage PM cells. These markers were also expressed in subsets of interstitial cells, most likely reflecting their common embryological provenance from migrating mesonephric cells. Although not strictly specific for PM cells, these markers are likely to be useful in studying the biology of early PM cells in the fetal testis.

Use of the Vector (TM) scaling unit in supportive periodontal therapy: a subjective patient evaluation

Background: Patient discomfort is one reason for poor compliance with supportive periodontal therapy (SPT). The aim of this study was to compare the levels of discomfort during SPT, using the Vector (TM) system and treatment with a conventional ultrasonic scaler. Methods: Forty-six patients with an SPT programme were debrided using both the Vector (TM) system and a conventional piezo-electric scaler (Sirona (TM)) in a split mouth design. A visual analogue scale was used to evaluate of pain scores upon completion of treatment. A verbal response scale(VRS) was used to assess discomfort, vibration and noise associated with the scaling system, as well as the volume and taste of the coolant used by these systems. Results: Patients instrumented with the Vector (TM) system experienced approximately half the amount of pain compared with the conventional ultrasonic scaling system. The VRS showed that the Vector (TM) system caused less discomfort than the conventional ultrasonic scaling system when assessed for pain, vibration, noise and volume of coolant. These findings were all statistically significant. There was, however, no statistically significant difference between the two systems when assessed for taste. Conclusion: During SPT the Vector (TM) system caused reduced discomforting sensations compared with conventional methods and may be useful in improving compliance with SPT programmes.

Comparative evaluation of microscopic car-following behavior

Microscopic traffic-simulation tools are increasingly being applied to evaluate the impacts of a wide variety of intelligent transport, systems (ITS) applications and other dynamic problems that are difficult to solve using traditional analytical models. The accuracy of a traffic-simulation system depends highly on the quality of the traffic-flow model at its core, with the two main critical components being the car-following and lane-changing models. This paper presents findings from a comparative evaluation of car-following behavior in a number of traffic simulators [advanced interactive microscopic simulator for urban and nonurban networks (AIMSUN), parallel microscopic simulation (PARAMICS), and Verkehr in Statiten-simulation (VISSIM)]. The car-following algorithms used in these simulators have been developed from a variety of theoretical backgrounds and are reported to have been calibrated on a number of different data sets. Very few independent studies have attempted to evaluate the performance of the underlying algorithms based on the same data set. The results reported in this study are based on a car-following experiment that used instrumented vehicles to record the speed and relative distance between follower and leader vehicles on a one-lane road. The experiment was replicated in each tool and the simulated car-following behavior was compared to the field data using a number of error tests. The results showed lower error values for the Gipps-based models implemented in AIMSUN and similar error values for the psychophysical spacing models used in VISSIM and PARAMICS. A qualitative drift and goal-seeking behavior test, which essentially shows how the distance headway between leader and follower vehicles should oscillate around a stable distance, also confirmed the findings.