Are foot and ankle characteristics associated with falls in people with rheumatoid arthritis? A prospective study.

OBJECTIVE: To determine whether foot and ankle characteristics are associated with falls in people with rheumatoid arthritis (RA). METHODS: Two hundred and one adults with RA were recruited from rheumatology outpatient clinics in Auckland, New Zealand. Clinical characteristics, common fall risk factors, and foot and ankle variables were measured. Participants were prospectively studied for 12 months, to record the occurrence of falls using falls diaries. Logistic regression analysis identified baseline variables which were independent predictors of falls over the 12 months. RESULTS: Eighty-four (42%) participants fell at least once and 39 (19%) experienced multiple (>1) falls over the 12-month follow-up period. In logistic regression analysis, including age and significant baseline variables in bivariate analysis but not baseline fall history, presence of foot or ankle tender joints (odds ratio (OR) 1.95, P=0.034) and psychotropic medication (OR 2.35, P=0.025) were independent predictors of prospective falls. However, when baseline fall history was included in the analysis, psychotropic medication (OR 2.34, P=0.025) and baseline fall history (over the preceding 12 months) (OR 2.27, P=0.008) were independent predictors of prospective falls. CONCLUSION: Foot and ankle characteristics are not associated with falls in people with RA, independent of prior falls. Enquiry about prior falls and psychotropic medications may assist in identifying patients with RA who are at high risk of future falls. This article is protected by copyright. All rights reserved

Reliability of the Tekscan Matscan® System for the Measurement of Postural Stability in Older People With Rheumatoid Arthritis

Postural stability can be measured in clinical and research settings using portable plantar pressure systems. People with rheumatoid arthritis (RA) have decreased postural stability compared to non-RA populations and impaired postural stability is associated with falls in people with RA. The purpose of this study was therefore to investigate the reliability of the TekScan MatScan® system in assessing postural stability in people with RA

An evaluation of seasonal variations in footwear worn by adults with inflammatory arthritis: a cross-sectional observational study using a web-based survey

Background: Foot problems are common in adults with inflammatory arthritis and therapeutic footwear can be effective in managing arthritic foot problems. Accessing appropriate footwear has been identified as a major barrier, resulting in poor adherence to treatment plans involving footwear. Indeed, previous New Zealand based studies found that many people with rheumatoid arthritis and gout wore inappropriate footwear. However, these studies were conducted in a single teaching hospital during the New Zealand summer therefore the findings may not be representative of footwear styles worn elsewhere in New Zealand, or reflect the potential influence of seasonal climate changes. The aim of the study was to evaluate seasonal variations in footwear habits of people with inflammatory arthritic conditions in New Zealand. Methods: A cross-sectional study design using a web-based survey. The survey questions were designed to elicit demographic and clinical information, features of importance when choosing footwear and seasonal footwear habits, including questions related to the provision of therapeutic footwear/orthoses and footwear experiences. Results: One-hundred and ninety-seven participants responded who were predominantly women of European descent, aged between 46–65 years old, from the North Island of New Zealand. The majority of participants identified with having either rheumatoid arthritis (35%) and/or osteoarthritis (57%) and 68% reported established disease (>5 years duration). 18% of participants had been issued with therapeutic footwear. Walking and athletic shoes were the most frequently reported footwear type worn regardless of the time of year. In the summer, 42% reported wearing sandals most often. Comfort, fit and support were reported most frequently as the footwear features of greatest importance. Many participants reported difficulties with footwear (63%), getting hot feet in the summer (63%) and the need for a sandal which could accommodate a supportive insole (73%). Conclusions: Athletic and walking shoes were the most popular style of footwear reported regardless of seasonal variation. During the summer season people with inflammatory arthritis may wear sandals more frequently in order to accommodate disease-related foot deformity. Healthcare professionals and researchers should consider seasonal variation when recommending appropriate footwear, or conducting footwear studies in people with inflammatory arthritis, to reduce non-adherence to prescribed footwear

Effects of foot and ankle devices on balance, gait and falls in adults with sensory perception loss

Foot and ankle devices are being developed as a method of preventing people with sensory perception loss sustaining a fall. Such devices are believed to work by reducing the likelihood of a fall by improving the balance and gait of the user.The objective of the review was to evaluate the effectiveness of foot and ankle devices for the prevention of falls and the improvement of balance and gait in adults with sensory perception loss.Participants were community-dwelling adults with bilateral pathological sensory perception loss.The current review evaluated any foot or ankle device, including but not restricted to, all types of footwear (therapeutic and retail), insoles (customized and prefabricated) and ankle-foot orthoses (AFOs).In the absence of randomized controlled trials (RCT), the review considered experimental and epidemiological study designs, except case series, individual case reports and descriptive cross-sectional studies.The primary outcome was number of falls. Secondary outcome measures were clinical or laboratory measures of balance or gait.A search for published and unpublished literature from inception to March 2015 written in the English language was conducted across a number of major electronic databases. A three-step search strategy was developed using MeSH terminology and keywords to ensure all that relevant materials are captured.Methodological quality of included studies was assessed by two reviewers, who appraised each study independently, using standardized Joanna Briggs Institute (JBI) critical appraisal tools.Quantitative data were extracted from the studies that were identified as meeting the criteria for methodological quality using the standardized JBI data extraction tools.Due to the heterogeneity of populations, interventions and outcome measures, meta-analyses were not possible and results are presented in narrative form.Nine trials (from 10 papers) involving 238 participants, (14 with multiple sclerosis and 16 with idiopathic peripheral neuropathy, 150 with diabetic neuropathy) and 58 controls were included in the review. No study reported falls as an outcome measure. The results of the included studies found that in people with sensory perception loss, postural sway improved with vibrating insoles and AFO, altering the softness and texture of the top cover had no effect on postural sway, wearing footwear over long distances or AFOs improved step-to-step consistency, and no foot and ankle device was reported to have a negative effect on the balance or gait of people with sensory perception loss. The methodological quality of the included studies was poor. No study used a randomized controlled trial (RCT) methodology. No study incorporated a follow-up period or tested the intervention within the context of the intended clinical environment.There is limited evidence to suggest that footwear and insole devices can artificially alter postural stability and may reduce the step-to-step variability in adults with sensory perception loss. Varying the material properties of an insole does not notably affect static balance or gait

The interface between invasive species science and legal regulation, using Hymenopteran species and their pathogens as a model system

Biological invasions are one of the major causes of biodiversity decline on the planet. The key driver of the global movement of invasive species is international trade. As a response to trade driven invasive species risk, international and domestic regulations have been promulgated with the goal of managing the spread and impact of non-native species. My aims in this thesis were twofold. First, my goal was to review a subset of international and domestic regulations with a view to commenting on their fitness for purpose and suggesting potential improvements. Second, I used the example of non-native and invasive Hymenoptera, as well as their pathogens, to illustrate the risks posed by invasive species and gaps in their management. In order to assess international and domestic regulations, I reviewed the World Trade Organization’s (WTO) Agreement on Sanitary and Phytosanitary Measures, as well as associated disputes. I argue that the WTO’s regulatory system does, for the most part, allow domestic regulators to manage invasive species risk as they see fit. Subsequently, the focus of the thesis narrows to investigate New Zealand’s pre- and post-border regime managing invasive species. I argue that New Zealand’s pre-border approach represents international best practice, but the post-border management of species is fragmented. The power to manage invasive species has been delegated to sub-national and regional bodies, which typically approach invasive species management in different ways. This variation has led to regulatory inconsistencies in pests managed and funding allocated. There appears to be a substantial lack of planning in some spaces, such as the risk of aquatic invasions. I make recommendations to ameliorate these inconsistencies. My second aim involved the study of non-native and invasive Hymenoptera in New Zealand, as well as the pathogens they carry, in order to illustrate the risks posed by invasive species and gaps in their management. I show that the globally widespread invasive Argentine ant (Linepithema humile) may play a role in the pathogen dynamics and mortality of honey bee hives where the species occur sympatrically. Hives in the presence of Argentine ants suffered significantly higher mortality rates relative to hives without ants and always had higher levels of a honey bee pathogen Deformed wing virus. I demonstrate that honey bee pathogens are found in a range of invasive Hymenoptera in New Zealand. I amplify entire genomes of the honey bee virus Kashmir bee virus (KBV) from three species of non-native or invasive Hymenoptera (Argentine ants, common wasps and honey bees). I show that there is KBV strain variability within and between regions, but more between regions. Further, I demonstrate the result that as sampled KBV sequence length increases, so too does sampled diversity. These results highlight how ‘an’ invasive species is typically not alone: they carry a range of diseases that are almost always not considered in international and regional management plans. Patterns of non-native Hymenoptera carrying honey bee diseases were not restricted to New Zealand. I used mitochondrial DNA to find the likely origin of invasive populations of the globally distributed invasive German wasp. I demonstrate that German wasps show reduced genetic diversity in the invaded range compared to the native range. Populations in the introduced range are likely to have arrived from different source populations. In some regions there were likely multiple introductions. Other regions are genetically homogenous and represent potential areas for use of gene drive technologies. All four different honey bee pathogens assayed for were found in German wasp populations worldwide. These results highlight how the introduction of one exotic species likely brings a range of pathogens. This example of pathogens in Hymenoptera is likely to be true for nearly all non-native introductions. Many of the impacts of biological invasions, such as predation and competition, are relatively obvious and are frequently studied. However some, such as the impact of pathogens, are unseen and poorly understood. Legal regulation is often a post-hoc response implemented once a problem has already arisen. At a global level regulatory regimes operate relatively effectively. As the focus becomes more granular, such as the case of pathogens of Hymenoptera, fewer controls exists. This thesis helps to reduce uncertainty in this area as well as makes recommendations as to how these risks may be managed

The interface between invasive species science and legal regulation, using Hymenopteran species and their pathogens as a model system

Biological invasions are one of the major causes of biodiversity decline on the planet. The key driver of the global movement of invasive species is international trade. As a response to trade driven invasive species risk, international and domestic regulations have been promulgated with the goal of managing the spread and impact of non-native species. My aims in this thesis were twofold. First, my goal was to review a subset of international and domestic regulations with a view to commenting on their fitness for purpose and suggesting potential improvements. Second, I used the example of non-native and invasive Hymenoptera, as well as their pathogens, to illustrate the risks posed by invasive species and gaps in their management. In order to assess international and domestic regulations, I reviewed the World Trade Organization’s (WTO) Agreement on Sanitary and Phytosanitary Measures, as well as associated disputes. I argue that the WTO’s regulatory system does, for the most part, allow domestic regulators to manage invasive species risk as they see fit. Subsequently, the focus of the thesis narrows to investigate New Zealand’s pre- and post-border regime managing invasive species. I argue that New Zealand’s pre-border approach represents international best practice, but the post-border management of species is fragmented. The power to manage invasive species has been delegated to sub-national and regional bodies, which typically approach invasive species management in different ways. This variation has led to regulatory inconsistencies in pests managed and funding allocated. There appears to be a substantial lack of planning in some spaces, such as the risk of aquatic invasions. I make recommendations to ameliorate these inconsistencies. My second aim involved the study of non-native and invasive Hymenoptera in New Zealand, as well as the pathogens they carry, in order to illustrate the risks posed by invasive species and gaps in their management. I show that the globally widespread invasive Argentine ant (Linepithema humile) may play a role in the pathogen dynamics and mortality of honey bee hives where the species occur sympatrically. Hives in the presence of Argentine ants suffered significantly higher mortality rates relative to hives without ants and always had higher levels of a honey bee pathogen Deformed wing virus. I demonstrate that honey bee pathogens are found in a range of invasive Hymenoptera in New Zealand. I amplify entire genomes of the honey bee virus Kashmir bee virus (KBV) from three species of non-native or invasive Hymenoptera (Argentine ants, common wasps and honey bees). I show that there is KBV strain variability within and between regions, but more between regions. Further, I demonstrate the result that as sampled KBV sequence length increases, so too does sampled diversity. These results highlight how ‘an’ invasive species is typically not alone: they carry a range of diseases that are almost always not considered in international and regional management plans. Patterns of non-native Hymenoptera carrying honey bee diseases were not restricted to New Zealand. I used mitochondrial DNA to find the likely origin of invasive populations of the globally distributed invasive German wasp. I demonstrate that German wasps show reduced genetic diversity in the invaded range compared to the native range. Populations in the introduced range are likely to have arrived from different source populations. In some regions there were likely multiple introductions. Other regions are genetically homogenous and represent potential areas for use of gene drive technologies. All four different honey bee pathogens assayed for were found in German wasp populations worldwide. These results highlight how the introduction of one exotic species likely brings a range of pathogens. This example of pathogens in Hymenoptera is likely to be true for nearly all non-native introductions. Many of the impacts of biological invasions, such as predation and competition, are relatively obvious and are frequently studied. However some, such as the impact of pathogens, are unseen and poorly understood. Legal regulation is often a post-hoc response implemented once a problem has already arisen. At a global level regulatory regimes operate relatively effectively. As the focus becomes more granular, such as the case of pathogens of Hymenoptera, fewer controls exists. This thesis helps to reduce uncertainty in this area as well as makes recommendations as to how these risks may be managed

Foot and ankle characteristics associated with falls and falls risk in adults with rheumatoid arthritis

The thesis investigated whether foot and ankle characteristics are associated with falls or falls risk in adults with rheumatoid arthritis (RA). A systematic review of the incidence and risk factors for falls in people with RA found inconsistency in methods for collecting falls data and conflicting evidence about fall risk factors. The current study sought to extend our understanding of fall risk in people with RA through the inclusion of foot and ankle characteristics. The thesis consisted of a cross-sectional study followed by a 12-month prospective study of 201 adults with established RA. In the cross-sectional study, falls experienced in the preceding year were recorded (12-month fall history) and a range of clinical and foot and ankle characteristics were measured. Participants were then followed for 12 months to record the occurrence of prospective falls following the Prevention of Falls Network Europe (ProFaNE) consensus guidelines for falls research. Data analysis involved both univariate and multivariate analysis. Falls incidence for the cross-sectional study was 59%. The logistic regression analysis, controlling for age, identified (a) clinical and foot and ankle characteristics which were independently associated with falls in the preceding 12 months; and (b) clinical and foot and ankle characteristics that were independent predictors of prospective falls. Clinical and foot and ankle characteristics that were independently associated with falls in the preceding 12 months included cardiovascular disease (odds ratio (OR) 3.22, P=0.024), midfoot peak plantar pressure (OR 1.12 [for each 20 kPa increase], P=0.046) and foot-related disability and impairment (OR 1.17 [for each 3 point increase], P=0.005). Falls incidence for the 12-month prospective study was 42%. Clinical and foot and ankle characteristics found to be independent predictors of prospective falls (not controlling for 12-month fall history) included psychotropic medication (OR 2.35, P=0.025) and presence of foot or ankle tender joints (OR 1.95, P=0.034). When 12-month fall history was included in the analysis, psychotropic medication (OR 2.34, P=0.025) and 12-month fall history (OR 2.27, P=0.008) were independent predictors of falls. Falls are complex, multi-system events with multifactorial aetiologies. Therefore, no single risk factor can be identified as the cause of any given fall event. As such, the thesis presented a synthesis of the findings relating to the foot and ankle fall risk factors, with a hypothetical model on how these risk factors might be interrelated. Further work is required to test the hypotheses relating to interrelationships between foot and ankle fall risk factors. Clinical implications included a number of assessments that could be incorporated into routine clinical practice to identify or monitor fall risk in people with established RA. Future work is needed to confirm the study findings in people with early RA and to develop a tool to screen for falls risk, and predict falls, in people with RA. Future research could include dynamic tests of balance, 3D gait analysis of lower limb and foot function and assessment of lower leg muscle strength and ankle joint proprioception. In addition, further evaluation of the role of footwear in falls, in people with RA, is warranted. Qualitative research, exploring perceptions around falls and falls risk, and the development of expert consensus guidelines for participant grouping in falls data analysis, would benefit future RA falls research

The interface between invasive species science and legal regulation, using Hymenopteran species and their pathogens as a model system

Biological invasions are one of the major causes of biodiversity decline on the planet. The key driver of the global movement of invasive species is international trade. As a response to trade driven invasive species risk, international and domestic regulations have been promulgated with the goal of managing the spread and impact of non-native species. My aims in this thesis were twofold. First, my goal was to review a subset of international and domestic regulations with a view to commenting on their fitness for purpose and suggesting potential improvements. Second, I used the example of non-native and invasive Hymenoptera, as well as their pathogens, to illustrate the risks posed by invasive species and gaps in their management.   In order to assess international and domestic regulations, I reviewed the World Trade Organization’s (WTO) Agreement on Sanitary and Phytosanitary Measures, as well as associated disputes. I argue that the WTO’s regulatory system does, for the most part, allow domestic regulators to manage invasive species risk as they see fit. Subsequently, the focus of the thesis narrows to investigate New Zealand’s pre- and post-border regime managing invasive species. I argue that New Zealand’s pre-border approach represents international best practice, but the post-border management of species is fragmented. The power to manage invasive species has been delegated to sub-national and regional bodies, which typically approach invasive species management in different ways. This variation has led to regulatory inconsistencies in pests managed and funding allocated. There appears to be a substantial lack of planning in some spaces, such as the risk of aquatic invasions. I make recommendations to ameliorate these inconsistencies.   My second aim involved the study of non-native and invasive Hymenoptera in New Zealand, as well as the pathogens they carry, in order to illustrate the risks posed by invasive species and gaps in their management. I show that the globally widespread invasive Argentine ant (Linepithema humile) may play a role in the pathogen dynamics and mortality of honey bee hives where the species occur sympatrically. Hives in the presence of Argentine ants suffered significantly higher mortality rates relative to hives without ants and always had higher levels of a honey bee pathogen Deformed wing virus. I demonstrate that honey bee pathogens are found in a range of invasive Hymenoptera in New Zealand. I amplify entire genomes of the honey bee virus Kashmir bee virus (KBV) from three species of non-native or invasive Hymenoptera (Argentine ants, common wasps and honey bees). I show that there is KBV strain variability within and between regions, but more between regions. Further, I demonstrate the result that as sampled KBV sequence length increases, so too does sampled diversity. These results highlight how ‘an’ invasive species is typically not alone: they carry a range of diseases that are almost always not considered in international and regional management plans.   Patterns of non-native Hymenoptera carrying honey bee diseases were not restricted to New Zealand. I used mitochondrial DNA to find the likely origin of invasive populations of the globally distributed invasive German wasp. I demonstrate that German wasps show reduced genetic diversity in the invaded range compared to the native range. Populations in the introduced range are likely to have arrived from different source populations. In some regions there were likely multiple introductions. Other regions are genetically homogenous and represent potential areas for use of gene drive technologies. All four different honey bee pathogens assayed for were found in German wasp populations worldwide. These results highlight how the introduction of one exotic species likely brings a range of pathogens. This example of pathogens in Hymenoptera is likely to be true for nearly all non-native introductions.  Many of the impacts of biological invasions, such as predation and competition, are relatively obvious and are frequently studied. However some, such as the impact of pathogens, are unseen and poorly understood. Legal regulation is often a post-hoc response implemented once a problem has already arisen. At a global level regulatory regimes operate relatively effectively. As the focus becomes more granular, such as the case of pathogens of Hymenoptera, fewer controls exists. This thesis helps to reduce uncertainty in this area as well as makes recommendations as to how these risks may be managed.</p

Foot and ankle characteristics associated with falls in adults with established rheumatoid arthritis: a cross-sectional study.

BACKGROUND: People with rheumatoid arthritis (RA) have an increased risk of falls. The foot is a common site of pathology in RA and foot problems are reported in up to 90 % of patients with established disease. The aim of this study was to determine whether foot and ankle characteristics are associated with falls in people with RA. METHODS: Adults with RA were recruited from rheumatology outpatient clinics in Auckland, New Zealand. Participants reported whether they had fallen in the preceding year, and the number of falls. Clinical characteristics, common fall risk factors, and foot and ankle variables were measured. Univariate parametric and non-parametric analysis compared fallers and non-fallers on all variables to determine significant differences. Logistic regression analysis identified variables independently associated with falls. RESULTS: Two hundred and one participants were prospectively recruited. At least one fall in the preceding 12-months was reported by 119 (59 %) participants. Univariate analysis showed that fallers had significantly longer mean disease duration, more co-morbid conditions, an increase in lower limb tender joints, higher midfoot peak plantar pressures and were more likely to have a history of vascular disease than non-fallers. Fallers also reported greater difficulty with activities of daily living, increased fear of falling and greater self-reported foot impairment. Logistic regression analysis revealed that increased midfoot peak plantar pressures (odds ratio (OR) 1.12 [for each 20 kPa increase], 95 % confidence interval (CI) 1.00-1.25), self-reported foot impairment (OR 1.17 [for each three point increase], 95 % CI 1.05-1.31) and history of vascular disease (OR 3.22, 95 % CI 1.17-8.88) were independently associated with a fall in the preceding 12 months. CONCLUSIONS: Elevated midfoot peak plantar pressures, self-reported foot impairment and vascular disease are associated with falls in people with RA. Assessment of foot deformity, foot function and self-reported foot impairment may be of benefit when considering falls prevention strategies in people with RA. TRIAL REGISTRATION: Australia New Zealand Clinical Trial Registry (trial ACTRN12612000597897 )