Reproducibility of a knee and hip proprioception test in healthy older adults.

BACKGROUND: Proprioception can be assessed by measuring joint position sense (JPS). Most studies have focused on JPS of the knee joint while literature for other joints especially for hip JPS is scarce. Although some studies have evaluated proprioception of the knee joint, the reproducibility of methods has rarely been investigated. AIMS: To estimate intrasession reliability and agreement of an active-active JPS test for hip flexion/abduction and knee flexion in healthy older adults. METHODS: Nineteen healthy older adults participated in this study. The proprioception of the hip (flexion and abduction) and knee (flexion) were assessed in both legs using the "active-active" reproduction technique. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and limits of agreement (LOA) were estimated for relative angular error (RE), absolute angular error (AE), and variable angular error (VE). RESULTS: Reliability of our JPS test was substantial to almost perfect for the RE for both joints and legs (ICC values ranging from 0.75 to 0.93). We also found that the ICC values for AE were substantial for knee flexion and hip abduction of the left and right leg. The ICC results of VE showed poor reliability for hip and knee joints. SEM and LOA values for hip abduction were generally lower than for hip and knee flexion, indicating lower measurement error or more precise scores for the proprioception test of hip abduction. CONCLUSION(S): Proprioceptive acuity of the knee and hip joints in healthy older adults can be reliably assessed with an active-active procedure in a standing position with respect to relative and absolute error.

Euthanasia in the Netherlands: a claims data cross-sectional study of geographical variation.

BACKGROUND: The annual incidence of euthanasia in the Netherlands as a percentage of all deaths rose from 1.9% in 1990 to 4.4% in 2017. Scarce literature on regional patterns calls for more detailed insight into the geographical variation in euthanasia and its possible explanations. OBJECTIVES: This paper (1) shows the geographical variation in the incidence of euthanasia over time (2013-2017); (2) identifies the associations with demographic, socioeconomic, preferential and health-related factors; and (3) shows the remaining variation after adjustment and discusses its meaning. DESIGN, SETTING AND METHODS: This cross-sectional study used national claims data, covering all healthcare claims during 12 months preceding the death of Dutch insured inhabitants who died between 2013 and 2017. From these claims all euthanasia procedures by general practitioners were selected (85% of all euthanasia cases). Rates were calculated and compared at three levels: 90 regions, 388 municipalities and 196 districts in the three largest Dutch cities. Data on possibly associated variables were retrieved from national data sets. Negative binomial regression analysis was performed to identify factors associated with geographical variation in euthanasia. RESULTS: There is considerable variation in euthanasia ratio. Throughout the years (2013-2017) the ratio in the three municipalities with the highest incidence was 25 times higher than in the three municipalities with the lowest incidence. Associated factors are age, church attendance, political orientation, income, self-experienced health and availability of voluntary workers. After adjustment for these characteristics a considerable amount of geographical variation remains (factor score of 7), which calls for further exploration. CONCLUSION: The Netherlands, with 28 years of legal euthanasia, experiences large-scale unexplained geographical variation in the incidence of euthanasia. Other countries that have legalised physician-assisted dying or are in the process of doing so may encounter similar patterns. The unexplained part of the variation may include the possibility that part of the euthanasia practice may have to be understood in terms of underuse, overuse or misuse.

An international comparison of long-term care trajectories and spending following hip fracture.

OBJECTIVE: The objectives of this study are to compare the relative use of different postacute care settings in different countries and to compare three important outcomes as follows: total expenditure, total days of care in different care settings, and overall longevity over a 1-year period following a hip fracture. DATA SOURCES: We used administrative data from hospitals, institutional and home-based long-term care (LTC), physician visits, and medications compiled by the International Collaborative on Costs, Outcomes, and Needs in Care (ICCONIC) from five countries as follows: Canada, France, Germany, the Netherlands, and Sweden. DATA EXTRACTION METHODS: Data were extracted from existing administrative data systems in each participating country. STUDY DESIGN: This is a retrospective cohort study of all individuals admitted to acute care for hip fracture. Descriptive comparisons were used to examine aggregate institutional and home-based postacute care. Care trajectories were created to track sequential care settings after acute-care discharge through institutional and community-based care in three countries where detailed information allowed. Comparisons in patient characteristics, utilization, and costs were made across these trajectories and countries. PRINCIPAL FINDINGS: Across five countries with complete LTC data, we found notable variations with Germany having the highest days of home-based services with relatively low costs, while Sweden incurred the highest overall expenditures. Comparisons of trajectories found that France had the highest use of inpatient rehabilitation. Germany was most likely to discharge hip fracture patients to home. Over 365 days, France averaged the highest number of days in institution with 104, Canada followed at 94, and Germany had just 87 days of institutional care on average. CONCLUSION: In this comparison of LTC services following a hip fracture, we found international differences in total use of institutional and noninstitutional care, longevity, and total expenditures. There exist opportunities to organize postacute care differently to maximize independence and mitigate costs.

Differences in health care spending and utilization among older frail adults in high-income countries: ICCONIC hip fracture persona.

OBJECTIVE: This study explores differences in spending and utilization of health care services for an older person with frailty before and after a hip fracture. DATA SOURCES: We used individual-level patient data from five care settings. STUDY DESIGN: We compared utilization and spending of an older person aged older than 65 years for 365 days before and after a hip fracture across 11 countries and five domains of care as follows: acute hospital care, primary care, outpatient specialty care, post-acute rehabilitative care, and outpatient drugs. Utilization and spending were age and sex standardized.. DATA COLLECTION/EXTRACTION METHODS: The data were compiled by the International Collaborative on Costs, Outcomes, and Needs in Care (ICCONIC) across 11 countries as follows: Australia, Canada, England, France, Germany, the Netherlands, New Zealand, Spain, Sweden, Switzerland, and the United States. PRINCIPAL FINDINGS: The sample ranged from 1859 patients in Spain to 42,849 in France. Mean age ranged from 81.2 in Switzerland to 84.7 in Australia. The majority of patients across countries were female. Relative to other countries, the United States had the lowest inpatient length of stay (11.3), but the highest number of days were spent in post-acute care rehab (100.7) and, on average, had more visits to specialist providers (6.8 per year) than primary care providers (4.0 per year). Across almost all sectors, the United States spent more per person than other countries per unit ($13,622 per hospitalization, $233 per primary care visit, $386 per MD specialist visit). Patients also had high expenditures in the year prior to the hip fracture, mostly concentrated in the inpatient setting. CONCLUSION: Across 11 high-income countries, there is substantial variation in health care spending and utilization for an older person with frailty, both before and after a hip fracture. The United States is the most expensive country due to high prices and above average utilization of post-acute rehab care.

International comparison of health spending and utilization among people with complex multimorbidity.

OBJECTIVE: The objective of this study was to explore cross-country differences in spending and utilization across different domains of care for a multimorbid persona with heart failure and diabetes. DATA SOURCES: We used individual-level administrative claims or registry data from inpatient and outpatient health care sectors compiled by the International Collaborative on Costs, Outcomes, and Needs in Care (ICCONIC) across 11 countries: Australia, Canada, England, France, Germany, the Netherlands, New Zealand, Spain, Sweden, Switzerland, and the United States (US). DATA COLLECTION/EXTRACTION METHODS: Data collected by ICCONIC partners. STUDY DESIGN: We retrospectively analyzed age-sex standardized utilization and spending of an older person (65-90 years) hospitalized with a heart failure exacerbation and a secondary diagnosis of diabetes across five domains of care: hospital care, primary care, outpatient specialty care, post-acute rehabilitative care, and outpatient drugs. PRINCIPAL FINDINGS: Sample sizes ranged from n = 1270 in Spain to n = 21,803 in the United States. Mean age (standard deviation [SD]) ranged from 76.2 (5.6) in the Netherlands to 80.3 (6.8) in Sweden. We observed substantial variation in spending and utilization across care settings. On average, England spent $10,956 per person in hospital care while the United States spent $30,877. The United States had a shorter length of stay over the year (18.9 days) compared to France (32.9) and Germany (33.4). The United States spent more days in facility-based rehabilitative care than other countries. Australia spent $421 per person in primary care, while Spain (Aragon) spent $1557. The United States and Canada had proportionately more visits to specialist providers than primary care providers. Across almost all sectors, the United States spent more than other countries, suggesting higher prices per unit. CONCLUSION: Across 11 countries, there is substantial variation in health care spending and utilization for a complex multimorbid persona with heart failure and diabetes. Drivers of spending vary across countries, with the United States being the most expensive country due to high prices and higher use of facility-based rehabilitative care.

Differences in health outcomes for high-need high-cost patients across high-income countries.

OBJECTIVE: This study explores variations in outcomes of care for two types of patient personas-an older frail person recovering from a hip fracture and a multimorbid older patient with congestive heart failure (CHF) and diabetes. DATA SOURCES: We used individual-level patient data from 11 health systems. STUDY DESIGN: We compared inpatient mortality, mortality, and readmission rates at 30, 90, and 365 days. For the hip fracture persona, we also calculated time to surgery. Outcomes were standardized by age and sex. DATA COLLECTION/EXTRACTION METHODS: Data was compiled by the International Collaborative on Costs, Outcomes and Needs in Care across 11 countries for the years 2016-2017 (or nearest): Australia, Canada, England, France, Germany, the Netherlands, New Zealand, Spain, Sweden, Switzerland, and the United States. PRINCIPAL FINDINGS: The hip sample across ranged from 1859 patients in Aragon, Spain, to 42,849 in France. Mean age ranged from 81.2 in Switzerland to 84.7 in Australia, and the majority of hip patients across countries were female. The congestive heart failure (CHF) sample ranged from 742 patients in England to 21,803 in the United States. Mean age ranged from 77.2 in the United States to 80.3 in Sweden, and the majority of CHF patients were males. Average in-hospital mortality across countries was 4.1%. for the hip persona and 6.3% for the CHF persona. At the year mark, the mean mortality across all countries was 25.3% for the hip persona and 32.7% for CHF persona. Across both patient types, England reported the highest mortality at 1 year followed by the United States. Readmission rates for all periods were higher for the CHF persona than the hip persona. At 30 days, the average readmission rate for the hip persona was 13.8% and 27.6% for the CHF persona. CONCLUSION: Across 11 countries, there are meaningful differences in health system outcomes for two types of patients.

A methodology for identifying high-need, high-cost patient personas for international comparisons.

OBJECTIVE: To establish a methodological approach to compare two high-need, high-cost (HNHC) patient personas internationally. DATA SOURCES: Linked individual-level administrative data from the inpatient and outpatient sectors compiled by the International Collaborative on Costs, Outcomes, and Needs in Care (ICCONIC) across 11 countries: Australia, Canada, England, France, Germany, the Netherlands, New Zealand, Spain, Sweden, Switzerland, and the United States. STUDY DESIGN: We outline a methodological approach to identify HNHC patient types for international comparisons that reflect complex, priority populations defined by the National Academy of Medicine. We define two patient profiles using accessible patient-level datasets linked across different domains of care-hospital care, primary care, outpatient specialty care, post-acute rehabilitative care, long-term care, home-health care, and outpatient drugs. The personas include a frail older adult with a hip fracture with subsequent hip replacement and an older person with complex multimorbidity, including heart failure and diabetes. We demonstrate their comparability by examining the characteristics and clinical diagnoses captured across countries. DATA COLLECTION/EXTRACTION METHODS: Data collected by ICCONIC partners. PRINCIPAL FINDINGS: Across 11 countries, the identification of HNHC patient personas was feasible to examine variations in healthcare utilization, spending, and patient outcomes. The ability of countries to examine linked, individual-level data varied, with the Netherlands, Canada, and Germany able to comprehensively examine care across all seven domains, whereas other countries such as England, Switzerland, and New Zealand were more limited. All countries were able to identify a hip fracture persona and a heart failure persona. Patient characteristics were reassuringly similar across countries. CONCLUSION: Although there are cross-country differences in the availability and structure of data sources, countries had the ability to effectively identify comparable HNHC personas for international study. This work serves as the methodological paper for six accompanying papers examining differences in spending, utilization, and outcomes for these personas across countries.

The Effects of Texting, Sitting Surface Stability, and Balance Training on Simulated Driving Performance and Perceived Workload in Young and Older Drivers.

It has been shown that texting degrades driving performance, but the extent to which this is mediated by the driver's age and postural stability has not been addressed. Hence, the present study examined the effects of texting, sitting surface stability, and balance training in young and older adults' driving performance. Fifteen young (mean age = 24.3 years) and 13 older (mean age = 62.8 years) participants were tested in a driving simulator with and without texting on a smartphone and while sitting on a stable or unstable surface (i.e., a plastic wobble board), before and after a 30-min sitting balance training. Analyses of variance showed that texting deteriorated driving performance but irrespective of sitting surface stability. Balance training decreased the negative effects of texting on driving, especially in older adults. Perceived workload increased when drivers were texting, and balance training reduced perceived workload. Perceived workload was higher while sitting on the unstable surface, but less so after balance training. Path analyses showed that the effects on driving performance and perceived workload were (indirectly) associated with changes in postural stability (i.e., postural sway). The study confirms that texting threatens safe driving performance by challenging postural stability, especially in older adults. The study also suggests that it is important to further investigate the role balance training can play in reducing these negative effects of texting.

Assessing age-related balance deterioration: Visual or mechanical tasks?

BACKGROUND: Mediolateral balance assessment (MELBA) comprises tracking of predictable and unpredictable targets moving at increasing frequencies, using centre-of-mass feedback. The mediolateral-balance-assessment was shown to be sensitive to subtle age-related balance deterioration. However, it has been suggested that performance during ground-level tasks can be more sensitive to balance deterioration. METHODS: we developed a modified mediolateral-balance-assessment using tracking of surface translations with comparable waveforms (mechanical mediolateral-balance-assessment) to compare age sensitivity of the visual and mechanical mediolateral-balance-assessment, 15 older adults (68 SD 5 yr) and 12 young adults (30 SD 4 yr) performed both tasks. Phase-shift and gain between the CoM and either the visual target or the surface displacement for the visual and the mechanical mediolateral-balance-assessment, respectively, were calculated. To identify differences in tracking strategies between the visual and mechanical mediolateral-balance-assessment, phase-shift between trunk and leg angles was calculated. FINDINGS: Overall, older adults performed worse than young across the predictable and unpredictable tracking and visual and mechanical tasks. Of all mediolateral-balance-assessment performance descriptors, a significant interaction between age and task (visual or mechanical) was only found for the mean phase-shift. Post-hoc comparisons revealed significant age differences in the visual but not in the mechanical mediolateral-balance-assessment. Significant differences in tracking strategies were found between visual and mechanical mediolateral-balance-assessment with a greater decoupling of trunk and legs during the mechanical than the visual mediolateral-balance-assessment. INTERPRETATION: the visual mediolateral-balance-assessment was more sensitive to age-related balance deterioration than the mechanical mediolateral-balance-assessment, possibly because visual tracking elicits motor strategies that are more affected by ageing.

Where to Step? Contributions of Stance Leg Muscle Spindle Afference to Planning of Mediolateral Foot Placement for Balance Control in Young and Old Adults.

Stable gait requires active control of the mediolateral (ML) kinematics of the body center of mass (CoM) and the base of support (BoS) in relation to each other. Stance leg hip abductor (HA) muscle spindle afference may be used to guide contralateral swing foot placement and adequately position the BoS in relation to the CoM. We studied the role of HA spindle afference in control of ML gait stability in young and older adults by means of muscle vibration. Healthy young (n = 12) and older (age > 65 years, n = 18) adults walked on a treadmill at their preferred speed. In unperturbed trials, individual linear models using each subject's body CoM position and velocity at mid-swing as inputs accurately predicted foot placement at the end of the swing phase in the young [mean R2 = 0.73 (SD 0.11)], but less so in the older adults [mean R2 = 0.60 (SD 0.14)]. In vibration trials, HA afference was perturbed either left or right by vibration (90 Hz) in a random selection of 40% of the stance phases. After vibrated stance phases, but not after unvibrated stance phases in the same trials, the foot was placed significantly more inward than predicted by individual models for unperturbed gait. The effect of vibration was stronger in young adults, suggesting that older adults rely less on HA spindle afference. These results show that HA spindle afference in the stance phase of gait contributes to the control of subsequent ML foot placement in relation to the kinematics of the CoM, to stabilize gait in the ML direction and that this pocess is impaired in older adults.

Effects of constrained trunk movement on frontal plane gait kinematics.

Previously it has been shown that constraining step width in gait coincides with decreased trunk displacements. Conversely, external stabilization of the upper body in gait coincides with decreased step width, but this may in part be due to changes in passive dynamics of the leg. In the present study, trunk kinematics during gait were constrained without external stabilization by using an orthosis, to investigate whether step width and dynamic gait stability in the ML direction are changed in relation to trunk kinematics. Nine healthy young adults walked on a treadmill at three different speeds with no intervention and while wearing a thoracolumbar orthosis. Based on marker trajectories, trunk COM displacement, body COM displacement and velocity, step width, and margin-of-stability in ML direction were calculated. The results showed that the orthosis significantly reduced trunk and body COM displacements. As hypothesized, the restriction of trunk movement coincided with significantly decreased step width, while the margin-of-stability was not affected. These findings indicate that, when trunk movements are constrained, humans narrow step width, while maintaining a constant margin-of-stability. In conclusion, the present results in combination with previous work imply that in gait a reciprocal coupling between trunk kinematics and foot placement in the frontal plane subserves control of stability in the frontal plane.

Hip abductor neuromuscular capacity: A limiting factor in mediolateral balance control in older adults?

BACKGROUND: Mediolateral balance impairment is an important cause of falling in older adults. We aimed to investigate whether hip abductor muscular strength and/or position sense are limiting factors in mediolateral balance control. METHODS: Sixteen community-dwelling older adults performed three different mediolateral weight-shifting tasks, by tracking (1) a sinusoidally moving visual target, "visual-MELBA"; (2) a sinusoidally translating platform without explicit visual feedback, "mechanical-MELBA"; and (3) an unpredictable platform translation, "sudden-platform-translation." Balance performance was quantified for each task and correlated with hip abductor position sense, isometric strength, and peak hip abduction/adduction moments and moment rates. FINDINGS: Participants with better balance performance showed higher and faster hip abduction/adduction moment production during the tasks. Isometric hip abductor strength was significantly correlated with accuracy of tracking the visual target, while hip abductor position sense was associated with the bandwidth over which the mechanical target could be tracked and with a smaller delay between CoM movement and the sudden-platform movement. INTERPRETATION: Hip abductor muscles play an important role in mediolateral balance control. Accurate balance performance appears limited by lower hip abductor strength when explicit visual information on balance reduces the need for hip abductor proprioception, while proprioceptive acuity may limit balance performance when no explicit enhanced feedback is presented and required weight shifts have to be inferred from "normal" sensory information.

Effects of narrow base gait on mediolateral balance control in young and older adults.

The aim of this study was to examine the effect of narrowing step width on mediolateral (ML) center of mass (COM) kinematics and margin of stability (MOS) in young and older adults. Fourteen young and 18 healthy older adults were asked to walk on a treadmill at preferred speed, stepping on projected lines at their predetermined preferred step width (PSW) and at a 50% narrowed step width (NSW). Linear trunk accelerations were recorded by an inertial sensor, attached at the level of the lumbar spine and foot placement was determined from force sensors in the treadmill. Mediolateral peak-to-peak COM displacement, COM velocity and MOS within strides were estimated. Mean ML-COM displacement and velocity, which were significantly higher in older compared to young adults, were significantly reduced in the NSW condition while the variability of ML-COM velocity was increased in the NSW condition. A significant interaction effect of step width and age was found for ML-COM velocity, showing larger decreases in older adults in the NSW condition. Walking with NSW reduced the ML-MOS significantly in both groups while it was smaller in the older group. Although reductions of ML-COM displacement and velocity may occur as direct mechanical effects of reduced step width, the larger variability of ML COM velocity in the older adults suggests active control of ML COM movements in response to the reduced base of support. Given the effects on MOS, narrowing step width might challenge ML-balance control and lead to less robust gait especially in older adults.

Effects of hip abductor muscle fatigue on gait control and hip position sense in healthy older adults.

We experimentally investigated whether unilateral hip abductor muscle fatigue affected gait control and hip position sense in older adults. Hip abductor muscles were fatigued unilaterally in side-lying position in 17 healthy older adults (mean age 73.2 SD 7.7 years). Hip joint position sense was assessed by an active-active repositioning test while standing and was expressed as absolute and relative errors. Participants walked on a treadmill at their preferred walking speed, while 3D linear accelerations were collected by an inertial sensor at the lower back. Gait parameters, including step and stride time, local divergence exponents and harmonic ratio were quantified. In fatigued gait, stride time variability and step-to-step asymmetry in the frontal plane were significantly increased. Also a significantly slower mediolateral trunk movement in fatigued leg late stance toward the non-fatigued leg was observed. Despite these temporal and symmetry changes, gait stability in terms of the local divergence exponents was not affected by fatigue. Hip position sense was also affected by fatigue, as indicated by an increased relative error of 0.7° (SD 0.08) toward abduction. In conclusion, negative effects of fatigue on gait variability, step-to-step symmetry, mediolateral trunk velocity control and hip position sense indicate the importance of hip abductor muscles for gait control.

Influence of modified solid ankle-foot orthosis to be used with and without shoe on dynamic balance and gait characteristic in asymptomatic people.

BACKGROUND: Ankle-foot orthoses are usually used in combination with footwear. Shoe design can have a significant effect on kinematics of the lower limb joints and line of action of the ground reaction force during walking. But, ankle-foot orthosis-footwear combination is not appropriate for indoor barefoot walking in some Asian cultures. In this study, we have modified a solid ankle-foot orthosis in order to set it in the same position as a solid ankle-foot orthosis-footwear combination. OBJECTIVE: To investigate the effect of a modified solid ankle-foot orthosis; a solid ankle-foot orthosis which can be locked in different positions on gait and balance performance in comparison with a conventional solid ankle-foot orthosis, a common solid ankle-foot orthosis-shoe combination in asymptomatic adults. STUDY DESIGN: Cross sectional. METHODS: Two standard solid ankle-foot orthoses were manufactured with the ankle joint in neutral position. Then, one of these solid ankle-foot orthoses was modified in order to allow locking in a different alignment. Walk across, limit of stability, and sit-to-stand tests of the balance master system were performed while participants wore the modified solid ankle-foot orthosis aligned in 5°-7° anterior inclination without a shoe and a conventional solid ankle-foot orthosis-shoe combination. RESULTS: There was no significant change in walking speed, step length, and step width with the conventional and modified solid ankle-foot orthoses. In addition, movement velocity and maximum excursion of the center of gravity during the limit of stability test were not different, although the maximal forward excursion of the center of gravity was longer when wearing the modified solid ankle-foot orthosis compared to the conventional solid ankle-foot orthosis-shoe combination (P = 0.000). Sway velocity of the center of gravity did not change during the sit-to-stand test. CONCLUSION: The results demonstrated that the modified solid ankle-foot orthosis had the same effects as the conventional solid ankle-foot orthosis-shoe combination on the gait and balance performance of asymptomatic adults. Clinical relevance The findings of the present study can be used as the basis for further investigations on the efficacy of the modified solid ankle-foot orthoses in different neuromuscular populations in order to help people who do not wear shoes at home, as is the custom in some Asian cultures.