Self-reported Walking Distance Research Articles

Patient-reported outcomes after minimally invasive sacro-iliac joint surgery: a cohort study based on the Swedish Spine Registry.

There is conflicting evidence regarding treatment outcomes after minimally invasive sacroiliac joint fusion for long-lasting severe sacroiliac joint pain. The primary aim of our cohort study was to investigate change in patient-reported outcome measures (PROMs) after minimally invasive sacroiliac joint surgery in daily practice in the Swedish Spine Registry. Secondary aims were to explore the proportion of patients reaching a patient acceptable symptom score (PASS) and the minimal clinically important difference (MCID) for pain scores, physical function, and health-related quality of life outcomes; furthermore, to evaluate self-reported satisfaction, walking distance, and changes in proportions of patients on full sick leave/disability leave and report complications and reoperations. Data from the Swedish Spine Registry was collected for patients with first-time sacroiliac joint fusion, aged 21 to 70 years, with PROMs available preoperatively, at 1 or 2 years after last surgery. PROMs included Oswestry Disability Index (ODI), Numeric Rating Scale (NRS) for low back pain (LBP) and leg pain, and EQ-VAS, in addition to demographic variables. We calculated mean change from pre- to postoperative and the proportion of patients achieving MCID and PASS. 68 patients had available pre- and postoperative data, with a mean age of 45 years (range 25-70) and 59 (87%) were female. At follow-up the mean reduction was 2.3 NRS points (95% confidence interval [CI] 1.6-2.9; P < 0.001) for LBP and 14.8 points (CI 10.6-18.9; P < 0.001) for ODI. EQ-VAS improved by 22 points (CI 15.4-30.3, P < 0.001) at follow-up. Approximately half of the patients achieved MCID and PASS for pain (MCID NRS LBP: 38/65 [59%] and PASS NRS LBP: 32/66 [49%]) and physical function (MCID ODI: 27/67 [40%] and PASS ODI: 24/67 [36%]). The odds for increasing the patient's walking distance to over 1 km at follow-up were 3.5 (CI 1.8-7.0; P < 0.0001), and of getting off full sick leave or full disability leave was 0.57 (CI 0.4-0.8; P = 0.001). In the first 3 months after surgery 3 complications were reported, and in the follow-up period 2 reoperations. We found moderate treatment outcomes after minimally invasive sacroiliac joint fusion when applied in daily practice with moderate pain relief and small improvements in physical function.

Intermuscular adipose tissue in patients with systemic lupus erythematosus

ObjectivePatients with SLE frequently have debilitating fatigue and reduced physical activity. Intermuscular adipose tissue (IMAT) accumulation is associated with reduced physical exercise capacity. We hypothesised that IMAT is increased in...

Prosthetic use by persons with unilateral transfemoral amputation in a South African setting.

Due to limitations in provision of prosthetic care in South Africa, a screening tool to select transfemoral prosthetic candidates has been implemented. To describe prosthetic services, use and mobility of people with transfemoral amputation, identified as prosthetic candidates through the Guidelines for Screening of Prosthetic Candidates: Lower Limb, and to identify variables that might influence prosthetic use and mobility. Cross-sectional survey. The study population included all adults who received their first prosthesis from the Orthotic and Prosthetic Centre in the Western Cape between 1 June 2011 and 31 December 2014. Data were collected, with an adapted version of the Prosthetic Profile of the Amputee, from 43 participants, through telephonic interviews. Descriptive and inferential analysis, with the chi-square test, was done. The majority of participants were older than 50 years (77%). Most participants (35; 81%) used their prosthesis; however, only 42% (18) used it daily. A significant association ( p = 0.000) was found between prosthetic rehabilitation and self-reported prosthetic walking distance. Less than half of participants received prosthetic rehabilitation and only 10 (30%) could walk 500 steps and more without resting. Participants used their prosthetic leg, but experienced limitations in frequency of wear and mobility. Current findings showed that participants' prosthetic mobility was curtailed. In less-resourced settings, carefully selecting prosthetic candidates may be necessary to provide access to services. Prosthetic provision is advised to be followed up with prosthetic rehabilitation for favourable mobility outcomes.

Can we trust self-reported walking distance when determining EDSS scores in patients with multiple sclerosis? The Danish MS hospitals rehabilitation study

Background: In multiple sclerosis (MS), the Expanded Disability Status Scale (EDSS) reflects disease severity. Although parts of the EDSS are dependent on actual walking distance, self-reported statements are often applied. Objectives: The purpose of the present study was, therefore, to compare self-reported walking distance to actual walking distance to outline how this influences EDSS scoring. Methods: MS patients with EDSS 4.0–7.5 (n = 273) were included from the Danish MS hospitals rehabilitation study (n = 427). All patients subjectively classified their maximal walking distance according to one of seven categories (>500; 300–499; 200–299; 100–199; 20–99; 5–19; 0–4 m). Subsequently, actual maximal walking distance was assessed and EDSS was determined from both self-reported walking distance (EDSSself-report) and actual walking distance (EDSSactual). Results: In 145 patients (53%), self-reported walking distance was misclassified when compared to the actual walking distance. Misclassification was more frequent in patients using walking aids (64% vs. 44%, p < 0.05) and in patients with primary progressive MS (69%, p < 0.05). Misclassification of walking distance corresponded to incorrect EDSS scores (EDSSself-report vs EDSSactual) of ⩾0.5 point in 24%. Conclusion: In MS patients with EDSS 4.0–7.5, 53% misclassified their walking distance yielding incorrect EDSS scores in 24%. Therefore, correct EDSS determination must be based on measurement of actual walking distance.

Effects of Defensive Style Nordic Walking Intervention in Patients with Lumbar and Lower-Limb Osteoarthritis

Regular exercise is effective for improving physical functions and pain relief in patients with lumbar and lowerlimb osteoarthritis. However, some of the patients have difficulty in performing land-based exercises due to disease status. This study focused on defensive style Nordic walking as a land-based exercise the patients can perform and aimed to investigate the effects of defensive style Nordic walking intervention on functional performance and pain in patients with lumbar and lower-limb osteoarthritis with low walking capacity. After 10 weeks of non-intervention, thirteen patients participated in the defensive style Nordic walking intervention for 10 weeks. The sixty-minute Nordic walking exercise was conducted once a week. Self-reported maximum walking distance without a break of the patients was less than 1 km and eight patients usually use a cane while walking. Functional performance measurement was conducted before non-intervention, after non-intervention (before intervention), and after intervention periods. Pain was measured using visual analog scale before and after each exercise session. Indices to estimate mobility, lower-limb muscle strength, and balance ability were improved by the intervention as compared with the non-intervention. Pain score decreased immediately after one session of defensive style Nordic walking and throughout the intervention period. These results suggest that the defensive style Nordic walking is an effective landbased exercise to improve mobility, lower-limb muscle strength, balance, and pain relief in patients with lumbar and lower-limb osteoarthritis with low walking capacity.

Do perceived walking distance to and use of urban blue spaces affect self-reported physical and mental health?

A cross-sectional analysis among 1041 urban residents was done to examine associations between self-reported walking distance to and use of freshwater urban blue space and health-related quality of life in two German cities: a city with “poor” urban blue space supply (Bielefeld; 0.8% blue space) and one with “better” urban blue space supply (Gelsenkirchen; 3.0% blue space). Health-related quality of life was assessed with the SF-12v2, which measures residents’ self-reported mental and physical health. Results showed a significant association between use frequency and perceived walking distance to blue space. Blue space use was a better indicator of health outcomes than perceived walking distance. After controlling for green space, socio-economic and demographic variables, use frequency was associated with higher mental health in Gelsenkirchen. These cross-sectional findings suggest that blue space use increases the probability of being healthier in highly urbanised areas in cities with an appropriate amount of blue space.

Self-reported maximum walking distance in persons with MS may affect the EDSS

BackgroundIn persons with MS (PwMS), the Expanded Disability Status Scale (EDSS) is used to monitor disability progression. Scores between 4.0 and 7.0 are determined by maximum walking distance. Self-estimation of this value is often employed in clinic settings. ObjectiveTo examine the accuracy with which PwMS estimate their walking distance, and observe subsequent changes to the EDSS. MethodsThis prospective cohort study recruited PwMS with previously recorded EDSS of 3.5–7.0. Participants estimated their maximum walking distance and then walked as far as they could along a pre-specified course. Each distance was converted to an EDSS score, the “estimated EDSS” and the “actual EDSS”. Chi-Square analysis was used to compare EDSS scores. Logistic regression was used to determine predictors of inaccurate estimations. ResultsOf the 66 PwMS in this study, 43.9% had a difference in the actual EDSS compared to the estimated EDSS. Median estimated EDSS was 4.75 (range 3.0–7.0); after walking assessment, median actual EDSS was 5.0 (range 3.0–7.0), which represented a significant difference [X2 (df 64, N=66)=206.9; p<0.001]. Actual EDSS decreased in 9 PwMS (13.6%) and increased in 20 PwMS (30.3%). Logistic regression did not find any demographic/disease characteristic to be predictive of this discrepancy. ConclusionSome PwMS do not accurately estimate maximum walking distance; only 56.1% of PwMS accurately estimated their actual EDSS.

Does the effectiveness of core stability exercises correlate with the severity of spinal stenosis in patients with lumbar spinal stenosis?

Objective:To determine whether the effectiveness of core stability exercises correlates with the severity of spinal stenosis in patients with degenerative lumbar spinal stenosis.Methods:Forty-two patients with degenerative lumbar spinal stenosis treated in the department of orthopedics of our hospital between May 2013 and January 2016 were included in the study. All the patients performed core stability exercises once daily for six weeks, and the clinical outcomes were evaluated using Japanese Orthopaedic Association (JOA) score and self-reported walking capacity. The anteroposterior osseous spinal canal diameter was measured to evaluate the severity of spinal stenosis. The correlation between the stenosis degree and the differences of Japanese Orthopaedic Association score or self-reported walking capacity at baseline and after treatment were analyzed.Results:The patients were divided into three groups according to the spinal stenosis degree. In the three groups, there was no significant difference in JOA or self-reported walking distance at baseline (p>0.05) and after treatment (p>0.05). The JOA scores and self-reported walking distance were significantly increased after treatment (p<0.05) in any of the three groups when compared to the baseline. Also, there was no significant correlation between the stenosis degree and the difference of JOA (p>0.05) or self-reported walking distance (p>0.05).Conclusion:There was no significantcorrelation between the effectiveness of core stability exercises and the severity of spinal stenosis in patients with degenerative lumbar spinal stenosis.

Applicability of global positioning system for the assessment of walking ability in patients with arterial claudication

This study determined for the first time the clinical applicability of a global positioning system (GPS)-monitored community-based walking ability assessment in a large cohort of patients with peripheral artery disease (PAD). A multicenter study was conducted among PAD patients who complained of intermittent claudication. Patients equipped with a GPS device performed a community-based outdoor walk. We determined the number of technically satisfactory GPS recordings (attempt No. 1). Patients with unsatisfactory GPS recordings were asked to perform a second attempt (attempt No. 2). From the satisfactory recordings obtained after attempts No. 1 and No. 2, we analyzed several GPS parameters to provide clinical information on the patients' walking ability. Results are reported as median (interquartile range). A total of 218 patients performed an outdoor walk. GPS recordings were technically satisfactory in 185 patients (85%) and in 203 (93%) after attempts No. 1 and No. 2, respectively. The highest measured distance between two stops during community walking was 678m (IQR, 381-1333m), whereas self-reported maximal walking distance was 250m (IQR, 150-400m; P< .001). Walking speed was 3.6km/h (IQR, 3.1-3.9km/h), with few variations during the walk. Among the patients who had to stop during the walk, the stop durations were<10minutes in all but one individual. GPS is applicable for the nonsupervised multicenter recording of walking ability in the community. In the future, it may facilitate objective community-based assessment of walking ability, allow for the adequate monitoring of home-based walking programs, and for the study of new dimensions of walking in PAD patients with intermittent claudication.

Six-minute walk test closely correlates to “real-life” outdoor walking capacity and quality of life in patients with intermittent claudication

We used outdoor walking distance measured during 40 minutes as "real-life" outdoor walking capacity in 49 patients with intermittent claudication (IC). The outdoor walking distance was measured by a global positioning system application for a smartphone. The relationships of self-reported maximum walking distance (SR-MWD), the MWD on a graded treadmill test, and the 6-minute maximum walk distance (6MWD) vs outdoors walking capacity were investigated. Also studied were the associations of SR-MWD, MWD, and 6MWD with health-related quality of life assessed with the disease-specific instrument the Vascular Quality of Life Questionnaire (VascuQoL). In this prospective observational cohort study, 49 IC patients underwent an outdoor walking capacity test for 40 minutes, and MWD and 6MWD were measured. SR-MWD was recorded, and all subjects completed the VascuQoL questionnaire. Associations between the different walk estimates and outdoor walking capacity and health-related quality of life were investigated by correlation analysis (Spearman ρ). Outdoor walking distance during 40 minutes was a median 2495 m (range, 1110-3300 m). SR-MWD correlated moderately and MWD correlated strongly to outdoor walking capacity (r = 0.56 and r = 0.65; P < .001, respectively). The 6MWD test showed the largest correlation to the outdoor walking capacity (r = 0.78; P < .001). The 6MWD was the only test that showed correlations with the VascuQoL sum score (r = 0.53; P < .01) and all of the domain scores, whereas SR-MWD and MWD showed weak correlations to the VascuQoL. The distance walked during the 6-minute walk test is closely correlated to outdoor walking capacity and health-related quality of life in IC patients. Our data support the use of 6MWD for routine clinical evaluation of walking capacity in IC patients.

The Walking Impairment Questionnaire stair-climbing score predicts mortality in men and women with peripheral arterial disease

The Walking Impairment Questionnaire (WIQ) measures self-reported walking distance, walking speed, and stair-climbing ability in men and women with lower extremity peripheral arterial disease (PAD). We determined whether poorer WIQ scores are associated with higher all-cause and cardiovascular disease (CVD) mortality in individuals with and without PAD. We identified 1048 men and women with and without PAD from Chicago-area medical centers. Participants completed the WIQ at baseline and were monitored for a median of 4.5 years. Cox proportional hazards models were used to relate baseline WIQ scores with death, adjusting for age, sex, race, the ankle-brachial index (ABI), comorbidities, and other covariates. During follow-up, 461 participants (44.0%) died, including 158 deaths from CVD. PAD participants in the lowest baseline quartile of the WIQ stair-climbing scores had higher all-cause mortality (hazard ratio, 1.70; 95% confidence interval, 1.08-2.66, P = .02) and higher CVD mortality (hazard ratio, 3.11; 95% confidence interval, 1.30-7.47, P = .01) compared with those with the highest baseline WIQ stair-climbing score. Among PAD participants, there were no significant associations of lower baseline WIQ distance or speed scores with rates of all-cause mortality (P = .20 and P = .07 for trend, respectively) or CVD mortality (P = .51 and P = .33 for trend, respectively). Among non-PAD participants there were no significant associations of lower baseline WIQ stair-climbing, distance, or speed score with rates of all-cause mortality (P = .94, P = .69, and P = .26, for trend, respectively) or CVD mortality (P = .28, P = .68, and P = .78, for trend, respectively). Among participants with PAD, lower WIQ stair-climbing scores are associated with higher all-cause and CVD mortality, independently of the ABI and other covariates.

Dose-response relationship between walking and the attenuation of inherited weight

ObjectiveGenetic factors account for 40%–70% of the variation in body mass index (BMI). We sought to test whether moderate intensity physical activity affected parent–offspring relationships for body mass index and regional adiposity in 26,587 female and 6428 male walkers surveyed in the United States in 2000. MethodsSurvey questionnaires provided self-reported usual walking distance, height, weight, and waist circumference, and mother's and father's adiposity (1=lean, 2=normal, 3=overweight, and 4=very overweight). Regression analyses were used to test whether the contribution of parental adiposities to the walkers' body mass indexes and waist circumferences diminished with walking. ResultsIn the most sedentary group (walking<1.5km/d), average parental adiposity was a significant determinant of the walkers' body mass indexes and waist circumferences (female: P<10−15; male: P<10−13). Greater walking distance significantly diminished the effect of average parents' adiposity on the walkers' body mass indexes (female: P<10−10; male P=0.003) and waist circumferences (female: P<10−6; male P=0.01). Compared to the most sedentary female walkers, the effect of parental adiposity was reduced 36% for body mass indexes and 41% for waist circumferences (corresponding reductions in men were 36% and 46%, respectively). ConclusionThese results suggest that moderate intensity physical activity attenuates inheritance of both total and regional adiposity in a dose-dependent manner.

Exercise treadmill testing in patients with claudication, with and without diabetes

To compare symptoms and walking capacities of patients with and without diabetes reporting vascular-type claudication. We recorded self-reported maximal walking distance, maximal walking distance on treadmill test (3.2 km h(-1) , 10% slope), exercise transcutaneous oxygen pressure DROP index [limb transcutaneous oxygen pressure (TcpO2) changes from rest minus chest TcpO2 changes from rest] and symptoms on treadmill in 230 patients with diabetes and 982 patients without diabetes. Exercise-induced proximal and distal symptoms were analysed in the perspective of underlying proximal and distal ischaemia (DROP value < negative 15 mmHg). Self-reported maximal walking distance did not differ between groups, whereas maximal walking distance on treadmill test was lower in patients with diabetes vs. patients without diabetes (261 ± 257 and 339 ± 326 m, respectively; P < 0.05 when adjusted for potential confounders). In patients with ischaemia, the number of ischaemic areas (proximal and/or distal on right and/or left) was comparable between the two groups. Patients with diabetes had more distal ischaemia than patients without diabetes (38 vs. 29%, respectively; P < 0.01), whereas proximal ischaemia was similar between groups. The prevalence of lower-limb exercise-related symptoms without ischaemia was comparable between groups. There were more symptoms other than lower-limb pain in patients with diabetes than patients without diabetes (29.6 vs. 18.3%, respectively; P < 0.01). Patients with diabetes show more severe limitation on the treadmill and more non-limb symptoms than patients without diabetes, although self-reported walking capacity is comparable between the two groups. Using TcpO2, we confirm that patients with diabetes reporting claudication show more distal ischaemia than patients without diabetes, with no difference at the buttock level. Treadmill testing is of interest in patients with peripheral artery disease and diabetes.

Validity and Reproducibility of Self-report Measures of Walking Capacity in Lumbar Spinal Stenosis

Measurement (validity) study. Examine validity and reproducibility of self-report measures of walking capacity for use in patients with lumbar spinal stenosis (LSS). Treatment outcomes in patients with LSS are often determined using data from self-report questionnaires. Despite some validity evidence available to support the use of self-report instruments in the evaluation of walking capacity in LSS, it is not certain that the construct being tapped using any of the self-report measures is, in fact, walking capacity. Validity of the Physical Function Scale of the Swiss Spinal Stenosis Questionnaire, the Oswestry Disability Index (ODI), self-predicted walking capacity (distance in meters) and a number of single item walking capacity questions was evaluated through comparison with a criterion measure of walking capacity, the Self-Paced Walking Test, in patients with LSS. Test-retest reproducibility was also examined for each of the self-report measures. Subjects included 49 patients (65.8 ± 10.0 years of age) with LSS confirmed on imaging and by a spine specialist surgeon. The measures found to be most highly associated with the criterion Self-Paced Walking Test were the walking distance item from the ODI (r = 0.83) and self-reported walking capacity in meters (with the aid of a distance reference) (r = 0.80). Reported walking capacity in meters had the lowest test-retest reproducibility (intraclass correlation coefficient = 0.65) of the measures studied. This study provides new information to help guide health professionals and researchers in the selection of appropriate outcome tools when examining walking in an LSS population. Study results support the use of the Physical Function Scale, self-reported walking distance, and the walking specific items from the ODI and the Physical Function Scale.

Access to Public Transit and Its Influence on Ridership for Older Adults in Two U.S. Cities

Growth in the population of older adults (age 60 and above) in coming years will challenge urban planners and transportation managers to provide travel options that support autonomy. To investigate barriers that older adults experience in using public transit, this research explores associations between older adults who do and do not ride fixed-route public transit and their neighborhood walking access to buses and trains. The research tests whether or not the distance between a trip origin or destination and a transit stop or station is a significant factor in predicting frequency of transit ridership. Data from a survey of older adults in California and New York is used to regress older adults’ frequency of riding public transit against explanatory variables, including demographic and socioeconomic variables, access and mobility measures, and neighborhood characteristics. Findings suggest that self-reported walking distance to transit has a statistically significant influence—in San Jose, California, but not in Buffalo, New York—in predicting transit ridership frequency. Drivers are more sensitive to walking distance than nondrivers. Models estimate that in San Jose, each additional five minutes in perceived walking time to transit decreases transit ridership frequency by five percent for nondrivers and by 25 percent for drivers. Older adults are likely to ride transit more often if they are male, nonwhite, and low income.

Measures of Walking in Lumbar Spinal Stenosis: Criterion Validity

Measurement of walking capacity in lumbar spinal stenosis (LSS) populations is important for the assessment of physical function, treatment outcomes, and monitoring of the natural progression of the condition. PURPOSE: The primary purpose of this study was to examine criterion validity evidence for the use of a number of self-report instruments and a standardized treadmill protocol as surrogate measures of walking capacity in persons with LSS using a 'self paced walking test' as the criterion measure. A secondary objective was to determine the reliability of the criterion measure, the 'self paced walking test.' METHODS: Subjects had been diagnosed with LSS confirmed by MRI/CT imaging, had LSS associated walking limitations and were >50 years of age. Data collection involved three visits, 2-7 days apart. For the first two visits, subjects completed a self paced walking test on an indoor track during one visit and treadmill protocol during the other (in random order), as well as a questionnaire addressing walking capacity. A second self paced walking test was always completed during the third visit. Spearman correlation coefficients were used to examine associations, while an intraclass correlation coefficient (ICC) was used to examine reliability. RESULTS: The sample consisted of 26 subjects with a mean age of 67, 62% of whom were female. Mean distance walked was 1209±1510m in the self paced walking test and 794±745m in the treadmill test. Mean self-reported walking distance was 1620±2390m. Total distance walked in the self paced walking test was highly correlated with total distance walked during the treadmill test (r=0.89), self-reported walking distance (r=0.83), and mean Swiss Spinal Stenosis Physical Function Scale score (r=−0.78). Data for two administrations of the self paced walking test were available for 16 subjects, yielding an ICC = 0.98 and R2=0.95. CONCLUSION: Preliminary results suggest that a treadmill protocol may best represent walking capacity in persons with LSS if a 'self paced walking test' is not feasible, although an underestimation in distance can be anticipated.

Prosthetic device provision to landmine survivors in bosnia and herzegovina: outcomes in 3 ethnic groups

Burger H, Marinček Č, Jaeger RJ. Prosthetic device provision to landmine survivors in Bosnia and Herzegovina: outcomes in 3 ethnic groups. Arch Phys Med Rehabil 2004;85:19–28. Objective To determine differences in prosthetic provision, use, and effectiveness among unilateral lower-extremity amputees from 3 ethnic groups in Bosnia and Herzegovina. Design Case series with a consecutive sample of patients seen in field clinics. Setting Multiple field clinics in Bosnia and Herzegovina from October 1998 to May 2002. Participants A total of 671 patients were examined, and information about their prosthetic history was recorded from observation or verbal responses. The majority of the amputations resulted from injuries inflicted by landmines. Interventions Not applicable. Main outcome measures Self-reported walking distance per day, prosthesis functionality (functional or nonfunctional as assessed by a physician and a prothetist), prosthesis status (broken or nonbroken as assessed by a physician and a prothetist), and employment status. Results Ethnic groups differed significantly in types of prostheses provided, functional status of the prostheses, and use of the prostheses for community ambulation. Conclusion Prosthetic devices and delivery of rehabilitation services for unilateral lower-extremity amputees differed between ethnic groups. Despite these differences, functional prosthetic devices increased mobility. Persons in all 3 ethnic groups with functional prostheses were more mobile than persons with nonfunctional prostheses. The employment rate was higher for people with functional prostheses.

Gender and age differences in plasma carnitine, muscle strength, and exercise tolerance in haemodialysis patients.

Haemodialysis patients have impaired exercise tolerance that may be related to impaired carnitine availability and/or alterations in carnitine metabolism. As carnitine metabolism is sex- and age-related, we examined plasma free and esterified carnitine concentrations, muscle strength, and estimated exercise tolerance in female (n=51) and male (n=63) patients of different ages (18-86 years). Concentrations of free carnitine and acetylcarnitine were determined in the plasma of patients. Isometric handgrip strength was measured using a dynamometer while exercise tolerance was predicted from scores for self-reported walking distance on the level and on an incline. Plasma total carnitine concentration in the females was significantly lower than that of males (35.4+/-1.3 and 42.4+/-1.4 micro mol/l, respectively, P<0.01). This was almost entirely due to the lower plasma free carnitine concentration of females when compared with the males (20.6+/-0.9 and 26.3+/-1.1 micro mol/l, respectively, P<0.05). Furthermore, plasma free carnitine concentrations were negatively correlated with age in females (r=-0.45, P<0.001) even when the linear effects of haemoglobin, albumin, body weight, time on dialysis, and muscle strength were removed from the regression analysis (partial correlation coefficient; pcc=-0.43, P=0.018), but not in the males (r=0.03, P>0.05). Isometric handgrip strength and estimated exercise tolerance on the level were lower in females than males (138.9+/-10.9 and 259.0+/-15.2 N, P<0.001; and 3.5+/-0.2 and 4.3+/-0.2, P<0.05, respectively). Isometric handgrip strength and estimated exercise tolerance (walking distance on the level and on an incline) were positively correlated with plasma free carnitine concentrations in females, but not in the males. There was a strong relationship between plasma free carnitine concentrations and age in female patients, but not in males. It is unlikely that the reduction in plasma free carnitine in females was a direct causative factor in their reduced exercise tolerance, but probably reflects greater muscle de-conditioning/atrophy with age in female patients.

Natural history of claudication: Long-term serial follow-up study of 1244 claudicants

Objective: The purpose of this study was to delineate the natural history of claudication and determine risk factors for ischemic rest pain (IRP) and ischemic ulceration (IU) among patients with claudication. Methods: We prospectively collected data on 1244 men with claudication during a 15-year period, including demographics, clinical risk factors, and ankle-brachial index (ABI). We followed these patients serially with ABIs, self-reported walking distance (WalkDist), and monitoring for IRP and IU. We used Kaplan-Meier and proportional hazards modeling to find independent predictors of IRP and IU. Results: Mean follow-up was 45 months; statistically valid follow-up could be carried out for as long as 12 years. ABI declined an average of 0.014 per year. WalkDist declined at an average rate of 9.2 yards per year. The cumulative 10-year risks of development of IU and IRP were 23% and 30%, respectively. In multivariate analysis using several clinical risk factors, we found that only DM (relative risk [RR], 1.8) and ABI (RR, 2.2 for 0.1 decrease in ABI) predicted the development of IRP. Similarly, only DM (RR, 3.0) and ABI (RR, 1.9 for 0.1 decrease in ABI) were significant predictors of IU. Conclusion: This large serial study of claudication is, to our knowledge, the longest of its kind. We documented an average rate of ABI decline of 0.014 per year and a decline in WalkDist of 9.2 yards per year. Two clinical factors, ABI and DM, were found to be associated with the development of IRP and IU. Our findings may be useful in predicting the clinical course of claudication. (J Vasc Surg 2001;34:962-70.)

Physical function among older adults with knee pain: the role of pain coping skills.

To evaluate the association between pain coping skills and disability among older adults with knee pain. Baseline measures from 394 older adults with knee pain and disability who participated in a 30-month observational study were analyzed. Pain coping skills were correlated with self-reported disability and walking distance after controlling for covariates of disability. Pain coping skills were significantly associated with disability (P < 0.05) and distance walked (P < 0.05). Less catastrophic thinking and prayer, greater ignoring and reinterpretation of pain sensations, and stronger perceptions of pain control were associated with less disability and better physical function. Pain coping skills used by older adults with osteoarthritis and knee pain may play a significant role in determining disability.