Performance-based methods for measuring the physical function of patients with osteoarthritis of the hip or knee: a systematic review of measurement properties

OBJECTIVE: To systematically review the measurement properties (i.e. internal consistency, reproducibility, validity, responsiveness and interpretability) of all performance-based methods which have been used to measure the physical function of patients with osteoarthritis of the hip or knee. METHODS: A systematic search was conducted in Medline, CINAHL, PsychINFO and Embase. Standardized criteria were applied to assess the quality of the clinimetric studies and the measurement properties. RESULTS: Twenty-six performance-based methods were included: 13 walking tests, two stair-climb tests, one chair test and ten multi-item tests. Three out of seven multi-activity tests were tested for internal consistency and two were rated positively. Fourteen tests were tested for reliability and five were rated positively. The absolute measurement error (agreement) was assessed for 10 tests. Only one test received a positive rating. Fourteen tests were tested for construct validity. Only two tests received positive ratings. Responsiveness was assessed for 12 tests, but none of them received a positive rating. A lot of indeterminate ratings were given, mostly for small studies or non-optimal analyses. CONCLUSION: Many more well-designed studies are needed to assess the measurement properties of performance-based methods. More importantly, however, before one can make a justified choice of a particular performance-based method, consensus is needed on what activities should be included in a performance-based test for patients with hip or knee osteoarthritis and which aspects of function should be measured.     

Visualization of the retinal image in an eye model with spherical and aspheric, diffractive, and refractive multifocal intraocular lenses

PURPOSE: To present a method that visually demonstrates how spherical, aspheric, diffractive, and refractive multifocal intraocular lenses (IOLs) process light received from the cornea. METHODS: Monochromatic green light was projected through an Average Cornea Eye (ACE) Model with a cornea in front of the IOL. The model simulates a human cornea with average spherical aberration and visualizes the converging bundle of light leaving the IOL. Additionally, a US Air Force target was projected through the model, and the projected (retinal) image was captured. Various IOLs of differing designs were evaluated using this test setup. Multifocal IOLs included the aspheric diffractive Tecnis ZM900 and ZMA00 lenses; the refractive ReZoom NXG1 lens; the spherical AcrySof ReSTOR SA60D3 apodized diffractive lens; and the spherical diffractive CeeOn 811E lens. Monofocal IOLs included the spherical CeeOnEdge 911A IOL and the aspheric SofPort LI61AO, AcrySof IQ SN60WF, and Tecnis Z9000 and ZA9003 IOLs. RESULTS: The light paths of the different diffractive and refractive multifocal IOLs showed the variations in the processing of incoming light, illustrating the functional differences of IOL concepts. The US Air Force target projections in the ACE Model gave an impression of the functional optical quality of the different lenses. The value of this visualization method was demonstrated by comparing the results with modulation transfer function measurements. CONCLUSIONS: This visualization technique furthers the understanding of the working principles and quality of the retinal images produced by different mono- and multifocal IOLs.     

A comparative study on the viscoelastic properties of human and animal lenses

A new method of compression between two parallel plates is used to measure the viscoelastic properties of whole and decapsulated human lenses and compare them with other animal species. Compressive load relaxation was performed by deforming the lens by 10% and measuring the force relaxation response for 100 s to obtain thickness, stiffness and relaxation of the induced loading force and Maxwell parameters for human, monkey, porcine and leporine whole and decapsulated lenses. Thickness and percentage loading force relaxation increased linearly with lens age, whereas stiffness and induced loading force increased exponentially. Human and monkey lenses aged at different rates. Loading force relaxation in a generalized Maxwell model was described by three time constants ranging from 1 to 1000 s. Compressive load relaxation is a very versatile method to study the viscoelastic properties of whole and decapsulated lenses and potentially also artificial accommodating lenses. The data presented in the study will help researchers choose the most suitable animal lenses based on the desired properties and age to be mimicked from the human lenses.     

Validation of the PROMIS Sleep Disturbance and Sleep-Related Impairment item banks in Dutch adolescents

Quality of Life Research - Sleep problems are common in adolescents and have a negative impact on daytime functioning. However, there is a lack of well-validated adolescent sleep questionnaires....     

A systematic review of instruments measuring foot function, foot pain, and foot-related disability in patients with rheumatoid arthritis

OBJECTIVE: To compose an inventory of instruments that have been described to measure foot function (i.e., pressure and/or gait parameters), foot pain, and foot-related disability in rheumatoid arthritis (RA), and to investigate the clinimetric quality of these measures. METHODS: A systematic search was conducted in Medline, CINAHL, EMBase, and Sportdiscus. Standardized criteria, extended with levels of evidence, were applied to assess the quality of the clinimetric studies and the properties (i.e., reliability, validity, and responsiveness) of the described instruments. RESULTS: A variety of measurement instruments were identified. Only 16 instruments have been studied for their measurement properties in RA patients: 7 for assessing foot function, 3 for measuring foot-related disability, and 6 for measuring both foot pain and foot-related disability. Thirteen instruments were rated for reliability, of which 10 were rated positively on different levels of evidence. No positive rating for absolute measurement error was applicable for any of the tests. Internal consistency was reported for 7 instruments; 3 assigned a positive rating. For 2 instruments, Rasch analysis was used to assess the methodologic quality. A positive rating was reported for goodness-of-fit only, not for item calibration. Seven instruments were rated for construct validity, and 3 assigned a positive rating. Only 2 instruments were rated positively for responsiveness. CONCLUSION: This review offers a basis for choosing the most appropriate instruments for measuring foot function, foot pain, and foot-related disability in RA patients, both for clinical practice and for research. Further research on the quality of these measures is urgently needed.     

Course and prognosis of knee complaints in general practice

OBJECTIVE: Patients frequently present with knee complaints in general practice. Information about the course and prognosis of knee complaints is needed to inform patients and facilitate decisions on referral and treatment. The objective of the study was to assess the course of knee complaints and to identify predictors of outcome in patients visiting their general practitioner with a new episode of knee complaints. METHODS: Data were collected by means of self-administered questionnaires. After 3 and 12 months of followup, the following outcomes were assessed: perceived recovery, change in pain, and change in physical functioning. As potential predictors of outcome, several sociodemographic variables, characteristics of the symptom, baseline scores of the outcome measures, and intra- and extra-individual variables were analyzed using multiple regression analyses. RESULTS: We included 251 patients with a new episode of knee complaints presented in general practice. Only 25% reported recovery after 3 months, increasing to 44% after 12 months. A history of knee complaints, a longer duration of the current episode of knee complaints, other coexisting musculoskeletal complaints, and a higher level of distress were associated with a worse prognosis. In the linear regression models, 41-53% of the variance in pain reduction and improvement in functioning could be explained by the predictors. The area under the receiver operating characteristic curves, estimating the predictive accuracy of the Cox regression models concerning perceived recovery, was 0.77 after 3 months and 0.72 after 12 months. CONCLUSION: Many patients did not recover after 12 months. Distress was found to be strongly associated with less pain reduction and less improvement in functioning.     

Quality of life after curative or palliative surgical treatment of pancreatic and periampullary carcinoma

BACKGROUND: Quality of life (QOL) is an important outcome measure after treatment of pancreatic and periampullary carcinoma. The aim of this prospective longitudinal study was to analyse QOL after surgery for resectable pancreatic or periampullary carcinoma. METHODS: Patients with potentially resectable tumours underwent pancreaticoduodenectomy (n = 72) or a double-bypass procedure (n = 42). They were asked to complete a questionnaire before laparotomy and at 2 weeks, 6 weeks, and 3, 6, 9 and 12 months after surgery. Fifty-nine patients completed a shortened questionnaire on a weekly basis. RESULTS: There was a temporary decrease in physical and gastrointestinal functioning after pancreaticoduodenectomy. A similar decrease in QOL was observed after double bypass, as well as decreases in mental functioning and overall QOL. Almost all QOL scores returned to preoperative values by about 3 months after surgery, although only briefly so in patients who had a double-bypass procedure. There were no differences between groups in the terminal stages of disease. A rapid decrease on all QOL scales was observed in the last 8 weeks before death. CONCLUSION: Surgery for pancreatic and periampullary carcinoma was not associated with irreversible impairment or protracted recovery of QOL. The relatively long plateau phase after recovery supports the argument for surgical treatment, including surgical palliation in selected patients.     

Health-related and overall quality of life of patients with chronic hip and knee complaints in general practice

Background: Information about quality of life of patients with chronic hip or knee complaints in general practice is scarce. This study describes the health-related and overall quality of life (HRQL) of these complaints. Methods: Data were obtained from a cohort study in general practice. HRQL at three months follow-up was analysed. HRQL was measured as: symptoms, physical, psychological and social functioning, and general health perceptions, using the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and the MOS 36-item short-form-health survey (SF-36). Overall quality of life was measured using a 5-point rating scale. Results: The results show that patients with chronic hip or knee complaints have a substantial lower HRQL compared to patients who had recovered from baseline hip or knee complaints. The largest effect was found on symptoms and physical functioning: up to 2.9 standard deviations below patients who had recovered from baseline hip or knee complaints. Scores of patients with both chronic hip and knee complaints were significantly worse than scores of patients with only knee complaints on most subscales. Conclusion: In patients with chronic hip or knee complaints the worst scores were seen on scales that measure symptoms and physical functioning, but still a substantially lower score was obtained for overall quality of life. Quality of life was poorer for patients with both chronic hip and knee complaints compared to those with chronic hip or knee complaints only.