Cynthia Kendell

Effect of mobility devices on orientation sensors that contain magnetometers.

Orientation sensors containing magnetometers use the earths magnetic field as a reference. Ferromagnetic objects may distort this magnetic field, leading to inaccurate orientation output. We explored the viability of these orientation sensors for motion analysis in an assistive mobility device rehabilitative setting. We attached two MTx orientation sensors (XSens; Enschade, the Netherlands), connected to the XBus Master data collection unit (XSens), to a plastic frame such that the relative angle between sensors was constant. We then moved a series of mobility devices in proximity to the plastic frame: two knee-ankle-foot orthoses (aluminum, stainless steel), one ankle-foot orthosis, two transtibial prostheses (exoskeletal, endoskeletal), two walkers (standard, Challenger Low Wide [Evolution Technologies; Port Coquitlam, Canada]), and two wheelchairs (Tango [OrthoFab; Quebec City, Canada], GTi [Quickie; Phoenix, Arizona]). For each mobility device, we calculated the average difference in relative angle between the baseline and peak angles for each of five trials. Errors ranged from less than 0.10 to 35.29 degrees, depending on the mobility device and frame positioning near the device. This demonstrated the large errors that can occur when magnetometer-based orientation sensors with mobility devices are used. While strategic orientation sensor placement on some mobility devices can minimize these errors to an acceptable level, testing protocols should be implemented to verify orientation sensor accuracy for these applications.

A novel approach to surface electromyography: an exploratory study of electrode-pair selection based on signal characteristics

A 3 × 4 electrode array was placed over each of seven muscles and surface electromyography (sEMG) data were collected during isometric contractions. For each array, nine bipolar electrode pairs were formed off-line and sEMG parameters were calculated and evaluated based on repeatability across trials and comparison to an anatomically placed electrode pair. The use of time-domain parameters for the selection of an electrode pair from within a grid-like array may improve upon existing electrode placement methodologies.

Impact of comorbidity and healthcare utilization on colorectal cancer stage at diagnosis: literature review

PurposeIndividuals diagnosed with cancer close to death have low access to enrollment in palliative care programs. The purpose of this literature review was to assess the usefulness of pre-diagnostic comorbidity and healthcare utilization as indicators of late-stage colorectal cancer (CRC) diagnosis, to help with early identification of individuals who may benefit from palliative care.MethodsA literature search was conducted in relevant databases using title/abstract terms which included “cancer,” “stage,” “diagnosis,” “determinants,” “predictors,” and “associated.” Included studies examined whether comorbidity and/or healthcare utilization had an impact on the stage at which CRC was diagnosed. A standardized data abstraction form was used to assess the eligibility of each study. Thirteen articles were included in the literature review. These studies were assessed and synthesized using qualitative methodology.ResultsWe found much heterogeneity among study variables. The findings of this literature review point to the presence of comorbidity and non-emergent healthcare utilization as having no association with late-stage diagnosis. Conversely, emergency room presentation (ERP) was associated with late-stage diagnosis.ConclusionsThe results of this literature review did not find strong evidence to suggest that comorbidity and healthcare utilization are potential indicators of late-stage diagnosis. However, ERP may be useful as a flag for consideration of prompt referral to palliative care. Additional research is required to identify potential indicators of late-stage diagnosis that may be available in administrative databases, particularly in the area of healthcare utilization.

Population-Based Longitudinal Study of Follow-Up Care for Patients With Colorectal Cancer in Nova Scotia

PURPOSE The purpose of this study was to examine colorectal cancer (CRC) follow-up care in Nova Scotia, Canada. More specifically, the objectives were to describe adherence to two elements of follow-up guidelines (colonoscopies and physician visits) and to identify factors associated with receiving at least guideline-recommended care. METHODS All patients with stage II or III CRC undergoing curative-intent surgery in Nova Scotia, Canada, were identified through the provincial cancer registry and anonymously linked to additional administrative health databases. For a 3-year follow-up period, beginning 1 year after the diagnosis date, descriptive statistics were calculated for physician visits and colonoscopies. Factors associated with receiving at least guideline-recommended care were identified using logistic regression. RESULTS Most patients received follow-up care from multiple physician specialties. In year 3, 58.1% of patients received oncologist follow-up care. Guideline adherence for colonoscopies was 52.4%, whereas guideline adherence for physician visits decreased from 41.9% to 25.4%. Receipt of at least guideline-recommended care was inversely associated with age and comorbidity for colonoscopy and inversely associated with age for physician visits. CONCLUSION Receipt of follow-up care from oncologists and primary care physicians, prolonged oncologist care, and receipt of care inconsistent with guideline recommendations suggest there may be potential issues with inefficient use of cancer system resources and integration of guidelines into follow-up care practices in Nova Scotia. Transitioning routine follow-up to primary care could potentially increase guideline adherence by improving access to and continuity of care. CRC may be well suited to targeted knowledge translation strategies to improve guideline adherence.

Gait adaptations of transfemoral prosthesis users across multiple walking tasks

Background: For people with lower extremity amputations, the decreased confidence and suboptimal gait associated with dynamic instability can negatively affect mobility and quality of life. Quantifying dynamic instability could enhance clinical decision making related to lower extremity prosthetics and inform future prosthetic research. Objective: To quantitatively examine gait adaptations in transfemoral amputees across various walking conditions. Study design: Cross-sectional study. Methods: Plantar-pressure data were collected from 11 individuals with unilateral transfemoral amputations using an in-shoe plantar-pressure measurement system while navigating rigid and soft ground, ramp, and stair conditions. Six parameters were examined: anterior–posterior and medial–lateral center-of-pressure direction changes, sensor cell loading frequency (cell triggering), maximum lateral force position, double support time, and stride time. Paired t-tests and analyses of variance were used to examine differences between limbs and walking conditions, respectively. Results: Values for medial–lateral center-of-pressure direction change, sensor cell loading frequency, and double support time were significantly greater on the intact limb than the prosthetic limb. Significant differences between conditions occurred only for anterior–posterior center-of-pressure direction change and double support time on the prosthetic limb. Conclusion: Higher values on the intact limb suggest that it plays a key role in maintaining stability and optimizing body progression during different tasks. Differences between participants, limbs, and walking condition indicate parameter sensitivity to adaptive gait strategies. Clinical relevance This plantar-pressure-based approach is a viable option for point-of-care evaluation of locomotor performance, across common various mobility tasks and activities of daily living. The information obtained could be valuable for prosthetic prescription and optimization of prosthetic fit and alignment, potentially improving mobility for prosthetic users with dynamic stability deficits.

Understanding dynamic stability from pelvis accelerometer data and the relationship to balance and mobility in transtibial amputees

This study investigated whether pelvis acceleration-derived parameters can differentiate between dynamic stability states for transtibial amputees during level (LG) and uneven ground (UG) walking. Correlations between these parameters and clinical balance and mobility measures were also investigated. A convenience sample of eleven individuals with unilateral transtibial amputation walked on LG and simulated UG while pelvis acceleration data were collected at 100Hz. Descriptive statistics, Fast Fourier Transform, ratio of even to odd harmonics, and maximum Lyapunov exponent measures were derived from acceleration data. Of the 26 pelvis acceleration measures, seven had a significant difference (p≤0.05) between LG and UG walking conditions. Seven distinct, stability-relevant measures appeared in at least one of the six regression models that correlated accelerometer-derived measures to Berg Balance Scale (BBS), Community Balance and Mobility Scale (CBMS), and Prosthesis Evaluation Questionnaire (PEQ) scores, explaining up to 100% of the variability in these measures. Of these seven measures, medial-lateral acceleration range was the most frequent model variable, appearing in four models. Anterior-posterior acceleration standard deviation and stride time appeared in three models. Pelvis acceleration-derived parameters were able to differentiate between LG and UG walking for transtibial amputees. UG walking provided the most relevant data for balance and mobility assessment. These results could translate to point of patient contact assessments using a wearable system such as a smartbelt or accelerometer-equipped smartphone.

Timely access and quality of care in colorectal cancer: a population-based cohort study using administrative data

BackgroundWhile efforts to improve cancer outcomes have typically focused on improving quality of care, recently, a growing emphasis has been placed on timely access to quality cancer care. This retrospective cohort study examines, at a population level, the relationship between quality and timeliness of colorectal cancer (CRC) care in a single Canadian province (Nova Scotia). Through the provincial cancer registry, we identified all residents diagnosed with invasive CRC between 2001 and 2005 that underwent a non-emergent resection. Using anonymized administrative databases that are individually linked at the patient level, we obtained clinicodemographic, diagnostic, and treatment event data. Selected charts were reviewed to ensure completeness of chemotherapy data.Performance on six quality indicators and the percentage of patients achieving wait-time benchmarks for diagnosis, surgery, and adjuvant therapy were calculated. The relationship between quality indicators and wait-time benchmarks was examined using logistic regression.ResultsWhere an association was identified, patients who received ‘higher quality care’ had longer wait times. Individuals who received a complete preoperative colonoscopy were less likely to meet benchmarks for time from presentation to diagnosis and from diagnosis to surgery. Those who received an appropriate radiation oncology consultation were less likely to meet benchmarks for time from diagnosis to surgery and from surgery to adjuvant therapy.ConclusionsAs governments and other organizations move forward with strategies to reduce wait times, they must also focus on how to define and monitor quality care, and consider the relationship between these two dimensions of health care. Similarly, when developing quality improvement initiatives, the impact on resource utilization and potential to create longer waits for care must be considered.

Understanding responses to gait instability from plantar pressure measurement and the relationship to balance and mobility in lower-limb amputees.

BACKGROUND Measuring responses to a more unstable walking environment at the point-of-care may reveal clinically relevant strategies, particularly for rehabilitation. This study determined if temporal measures, center of pressure-derived measures, and force impulse measures can quantify responses to surface instability and correlate with clinical balance and mobility measures. METHODS Thirty-one unilateral amputees, 11 transfemoral and 20 transtibial, walked on level and soft ground while wearing pressure-sensing insoles. Foot-strike and foot-off center of pressure, center of pressure path, temporal, and force impulse variables were derived from F-Scan pressure-sensing insoles. FINDINGS Significant differences (P<0.05) between level and soft ground were found for temporal and center of pressure path measures. Twenty regression models (R(2) ≤ 0.840), which related plantar-pressure-derived measures with clinical scores, consisted of nine variables. Stride time was in eight models; posterior deviations per stride in six models; mean CoP path velocity in five models; and anterior-posterior center of pressure path coefficient of variation, percent double-support time, and percent stance in four models. INTERPRETATION Center of pressure-derived parameters, particularly temporal and center of pressure path measures, can differentiate between level and soft ground walking for transfemoral and transtibial amputees. Center of pressure-derived parameters correlated with clinical measures of mobility and balance, explaining up to 84.0% of the variability. The number of posterior deviations per stride, mean CoP path velocity stride time, anterior-posterior center of pressure path coefficient of variation, percent double-support time, and percent stance were frequently related to clinical balance and mobility measures.

How do surgeons decide to refer patients for adjuvant cancer treatment? Protocol for a qualitative study.

BackgroundNon-small cell lung cancer, breast cancer, and colorectal cancer are commonly diagnosed cancers in Canada. Patients diagnosed with early-stage non-small cell lung, breast, or colorectal cancer represent potentially curable populations. For these patients, surgery is the primary mode of treatment, with (neo)adjuvant therapies (e.g., chemotherapy, radiotherapy) recommended according to disease stage. Data from our research in Nova Scotia, as well as others’, demonstrate that a substantial proportion of non-small cell lung cancer and colorectal cancer patients, for whom practice guidelines recommend (neo)adjuvant therapy, are not referred for an oncologist consultation. Conversely, surveillance data and clinical experience suggest that breast cancer patients have much higher referral rates. Since surgery is the primary treatment, the surgeon plays a major role in referring patients to oncologists. Thus, an improved understanding of how surgeons make decisions related to oncology services is important to developing strategies to optimize referral rates. Few studies have examined decision making for (neo)adjuvant therapy from the perspective of the cancer surgeon. This study will use qualitative methods to examine decision-making processes related to referral to oncology services for individuals diagnosed with potentially curable non-small cell lung, breast, or colorectal cancer.MethodsA qualitative study will be conducted, guided by the principles of grounded theory. The study design is informed by our ongoing research, as well as a model of access to health services. The method of data collection will be in-depth, semi structured interviews. We will attempt to recruit all lung, breast, and/or colorectal cancer surgeons in Nova Scotia (n ≈ 42), with the aim of interviewing a minimum of 34 surgeons. Interviews will be audiotaped and transcribed verbatim. Data will be collected and analyzed concurrently, with two investigators independently coding and analyzing the data. Analysis will involve an inductive, grounded approach using constant comparative analysis.DiscussionThe primary outcomes will be (1) identification of the patient, surgeon, institutional, and health-system factors that influence surgeons’ decisions to refer non-small cell lung, breast, and colorectal cancer patients to oncology services when consideration for (neo)adjuvant therapy is recommended and (2) identification of potential strategies that could optimize referral to oncology for appropriate individuals.

Factors influencing middle managers’ commitment to the implementation of innovations in cancer care

Objective To identify and illuminate influences on middle managers’ commitment to innovation implementation. Methods A qualitative study was conducted, employing the methods of grounded theory. Semi-structured interviews were used to collect data from middle managers (n = 15) in Nova Scotia and New Brunswick, Canada. Data were collected and analysed concurrently, using an inductive constant comparative approach. Data collection and analysis continued until theoretical saturation was reached. Results The data revealed middle managers contemplate two central issues in terms of their commitment to implementation, that is whether or not they fully engage in and support the implementation of a particular innovation. These issues are (1) ease of implementation and (2) potential benefit for patients. Middle managers’ views and expectations related to ease of implementation are influenced by available resources, fit with setting, and stakeholder buy-in. Their views on patient benefit are influenced by external evidence of benefit and local gaps in care. Conclusions These findings provide further insight into the factors that influence middle managers’ commitment to innovation implementation, and how middle managers consider these factors in the context of their work settings.