Assessing Lung Cancer Screening Programs under Uncertainty in a Heterogeneous Population

Background

Lung cancer screening can reduce cancer mortality. Most implementation studies focus only on low-dose computed tomography (LDCT) and clinical attributes of screening and do not include preferences of potential participants. In this study we evaluated the perceived value of screening programs based on LDCT, breath analysis (BA), or blood biomarkers (BB) according to the perspective of the target population.

Foot and ankle joint kinematics in rheumatoid arthritis cannot only be explained by alteration in walking speed

Rheumatoid arthritis (RA) manifests itself in the foot and ankle of RA patients. The foot and ankle joint kinematics of these patients differ from that of healthy subjects. However, the factors that lead to these differences are not yet fully understood. The aim of this study was to analyse the effect of walking speed and the disease process on foot and ankle joint kinematics of RA subjects. Gait recordings of 23 RA and 14 age-matched healthy subjects were performed and their foot and ankle joint kinematics were analysed during the stance phase of the gait cycle. Stance phase characteristics of the group of RA subjects and of the group of healthy subjects were compared. The healthy subjects walked at 100% (Vc), 75% (V75) and 50% (V50) of their comfortable walking speed. In a multi-level linear model significant differences between the two groups due to the factors walking speed and the disease process were analysed. The ankle dorsi-flexion, medial arch and hallux abduction motion at single-stance and toe-off were only influenced by the walking speed. The hallux maximum flexion at toe-off and the midfoot supination at single-stance were influenced by both the walking speed and the disease process. The hindfoot eversion motion at single-stance was only influenced by the disease process. In conclusion, the reduction of walking speed of RA subjects compared to healthy subjects does not explain all of the observed foot and ankle kinematics differences.     

Preferences for Colorectal Cancer Screening Techniques and Intention to Attend: a Multi-Criteria Decision Analysis

Background

Despite the expected health benefits of colorectal cancer screening programs, participation rates remain low in countries that have implemented such a screening program. The perceived benefits and risks of the colorectal cancer screening technique are likely to influence the decision to attend the screening program. Besides the diagnostic accuracy and the risks of the screening technique, which can affect the health of the participants, additional factors, such as the burden of the test, may impact the individuals’ decisions to participate. To maximise the participation rate of a screening program for a new colorectal cancer program in the Netherlands, it is important to know the preferences of the screening population for alternative screening techniques.

Objective

The aim of this study was to explore the impact of preferences for particular attributes of the screening tests on the intention to attend a colorectal cancer screening program.

Methods

We used a web-based questionnaire to elicit the preferences of the target population for a selection of colon-screening techniques. The target population consisted of Dutch men and women aged 55–75 years. The analytic hierarchy process (AHP), a technique for multi-criteria analysis, was used to estimate the colorectal cancer screening preferences. Respondents weighted the relevance of five criteria, i.e. the attributes of the screening techniques: sensitivity, specificity, safety, inconvenience, and frequency of the test. With regard to these criteria, preferences were estimated between four alternative screening techniques, namely, immunochemical fecal occult blood test (iFOBT), colonoscopy, sigmoidoscopy, and computerized tomographic (CT) colonography. A five-point ordinal scale was used to estimate the respondents’ intention to attend the screening. We conducted a correlation analysis on the preferences for the screening techniques and the intention to attend.

Results

We included 167 respondents who were consistent in their judgments of the relevance of the criteria and their preferences for the screening techniques. The most preferred screening method for the national screening program was CT colonography. Sensitivity (weight = 0.26) and safety (weight = 0.26) were the strongest determinants of the overall preferences for the screening techniques. However, the screening test with the highest intention to attend was iFOBT. Inconvenience (correlation [r] = 0.69), safety (r = 0.58), and the frequency of the test (r = 0.58) were most strongly related to intention to attend.

Conclusions

The multi-criteria decision analysis revealed the attributes of the screening techniques that are most important so as to increase intention to participate in a screening program. Even though the respondents may recognize the high importance of diagnostic effectiveness in the long term, their short-term decision to attend the screening tests may be less driven by this consideration. Our analysis suggests that inconvenience, safety, and frequency of the test are the strongest technique-related determinants of the respondents’ intention to participate in colorectal screening programs.     

The ICECAP-A instrument for capabilities: assessment of construct validity and test–retest reliability in a general Dutch population

Quality of Life Research - The ICEpop CAPability measure for Adults (ICECAP-A) assesses five capabilities that are important to one’s well-being. The instrument might be an important addition...     

The effects of walking speed on forefoot,hindfoot and ankle joint motion

BackgroundFoot and ankle joint kinematic differences have been identified between healthy subjects and subjects with various pathologies suffering from foot and ankle impairments. Changes in temporal factors such as walking speed and double stance time are also found in these pathological conditions. As such, in theory, these factors would also influence the kinematics and hence make it difficult to ascertain the effects of the disease on the kinematics. The aim of this study was to analyse foot and ankle kinematics from gait recordings of healthy subjects walking at comfortable and slower speeds.MethodsGait patterns of 14 healthy subjects were recorded. The subjects were first asked to walk at a comfortable speed and then at predefined speeds of 75% and 50% of their comfortable walking speed respectively. Temporal variables were calculated. Foot and ankle joint kinematics were determined from marker-recordings.FindingsThe subjects walked at mean velocities of 1.28 m/s, 0.97 m/s and 0.65 m/s. With decreasing walking speed the minimum tibio-talar plantar-flexion and maximum hallux dorsi-flexion at toe-off decreased significantly between 3° and 9°. The minimum medial arch at toe-off and minimum midfoot supination at mid-stance were significantly affected by the walking speed. The corresponding individual session differences were small (1°–2°), but the reliability was high and hence the differences were considered clinically relevant.InterpretationWalking speed significantly affected foot and ankle kinematics. Studies aiming to improve the understanding of the effects of foot and ankle pathologies on foot and ankle kinematics should take the walking speed into account.     

Comparison of electric stimulation methods for reduction of triceps surae spasticity in spinal cord injury

OBJECTIVES: To compare the effect of 3 methods of electric stimulation to reduce spasticity of the triceps surae in patients with complete spinal cord injury (SCI) and to investigate the carryover effect. DESIGN: Placebo-controlled study with repeated measurements after the interventions. SETTING: Research department affiliated with a rehabilitation hospital in the Netherlands. PARTICIPANTS: Ten patients with a complete SCI were recruited from the outpatient population of the rehabilitation hospital. All subjects had American Spinal Injury Association grade A impairment scores, except for one, who had grade C. The patients had no voluntary triceps surae contractibility. INTERVENTIONS: Forty-five minutes of cyclic electric stimulation of the agonist, antagonist, or dermatome of the triceps surae or a placebo approach. MAIN OUTCOME MEASURES: Outcome measures were the Modified Ashworth Scale (MAS), clonus score, and the H-reflex and M wave (H/M) ratio. The electromyographic response to a stretch of the soleus over the whole range of motion was also determined. The magnitude and ankle angle at which the electromyographic response started were calculated. RESULTS: Stimulation of the agonist provided a significant reduction in the MAS compared with the placebo approach (P<.001). There was no significant change in the H/M ratio or the electromyographic response amplitude after any of the stimulation methods, whereas stimulation of the antagonist muscle resulted in a significant reduction in the ankle angle at which the electromyographic response started, compared with the placebo approach (P<.037). CONCLUSIONS: Triceps surae stimulation reduces the MAS for that specific muscle, whereas the angle at which the reflex starts changes after antagonist stimulation.