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R W Chang

Publications and source records attributed to R W Chang.

At least 37 records · Page 2Linked to original sources
PubMed1996

Prognostic factors for functional outcome of total knee replacement: a prospective study.

BACKGROUND: The objective was to investigate whether baseline physical functioning, medical, psychosocial, or demographic variables predict functional outcome in patients undergoing total knee replacement. METHODS: A prospective cohort study was performed between December 1991 and August 1993. Consecutive, unilateral tricompartmental total knee replacement patients aged > or = 55 yr with osteoarthritis, who met criteria, were enrolled and evaluated one month before and 3 months after total knee replacement. The primary outcome measure was the Medical Outcome Study 36 Item Short Form Health Survey (known as the SF36) Physical Functioning Scale score. The outcome evaluator was not involved in patient care. RESULTS: A hierarchical multiple regression analysis was performed to calculate the contribution of baseline variables to TKR outcome. Of the 27% of outcome variance explained by the model, demographic variables accounted for 4%, psychosocial variables (motivation, role functioning-emotional, and social functioning) for 19% (p = .013), medical variables (previous reconstruction, comorbidity, body mass index, bodily pain) for 2%, and baseline physical function for 2%. CONCLUSIONS: Psychosocial variables are significantly related to total knee replacement functional outcome. Assessment of baseline psychological and social functioning may identify a subset of patients at risk for worse outcome. Specific interventions for these patients should be developed and evaluated as components of patient management prior to and after the procedure.

Activities of Daily Living↗
PubMed1996

Predictors of change in walking velocity in older adults.

OBJECTIVE: To determine factors that predict change in walking velocity in older people using a multivariate model. DESIGN: Longitudinal observational study. SUBJECTS: A total of 588 persons older than age 60, including subjects residing in a continuing care retirement community (CCRC) (n = 248), and homebound (n = 79) and ambulatory (n = 261) subjects. Mean age at baseline = 77. MEASUREMENT: Independent variables included demographics, physician measures of lower-extremity joint impairment and other musculoskeletal and neurological variables, comorbidities derived from physical examination and chart abstract, self-assessed arthritis pain, depression, and anxiety. The major dependent variables were 2- and 4-year decline in walking velocity below a threshold associated with nursing home placement. MAIN RESULTS: From baseline to Year 4, median walking velocity declined from 61.8 to 53.0 m/min, and the proportion of subjects above a threshold value of 11.5 m/min declined from 95.3% to 80.4%. Age, joint impairment, and weakness of quadriceps, measured at baseline, predicted 2-year and 4-year decline in walking velocity. CONCLUSIONS: The findings indicate that joint impairment and quadriceps strength contribute significantly to crossing a clinically significant threshold in walking velocity among older people over time. Future research is needed to determine whether these risk factors can be modified through preventive interventions such as muscle-strengthening exercises and pain medication.

Activities of Daily Living↗
PubMed1995

The determinants of walking velocity in the elderly. An evaluation using regression trees.

OBJECTIVE: To determine predictors of walking velocity in the elderly. METHODS: Five hundred thirty-two persons from 3 cohorts of elderly persons (retirement community, ambulatory care medical clinic, or chronically homebound population) performed a 10-foot (for the homebound subjects) or 50-foot (for all other subjects) walk time test and underwent a standardized interview, chart review, and clinical examination. The 73 independent variables that were evaluated included demographic, musculoskeletal, neurologic, psychologic, and other comorbidity items. Least-squares and least-absolute-deviation regression tree analyses were performed to determine the strongest predictive factors associated with walking velocity. RESULTS: Sampling cohort (homebound versus non-homebound), quadriceps strength, hip flexion strength, lumbosacral spine impairment, lower joint impairment, and education were found to be associated with walking velocity. Joint pain measures were not associated with walking velocity. CONCLUSION: Muscle strength variables are better predictors of walking velocity than are joint pain variables. Thus, clinical trials and observational studies using walking velocity as an outcome need to take into consideration the influence of muscle strength on this outcome variable.

Aged↗
PubMed1994

Alteration in multijoint dynamics in patients with bilateral knee osteoarthritis.

OBJECTIVE: To document the alterations of joint motion and torque in patients with bilateral knee osteoarthritis (OA), using a well-defined functional maneuver, the sit-to-stand (STS) task. METHODS: Twelve patients with bilateral knee OA and 12 age-, sex-, and height-matched control subjects performed the STS maneuver from a stool of a standard height at their natural speeds. A motion analysis system and 2 force platforms were employed to determine the dynamic joint motion and the resultant joint torques at the ankle, knee, and hip joints. RESULTS: The results showed that OA patients exhibited substantially reduced knee extension torques, accompanied by other alterations in initial sitting posture (more extended knee and more plantar-flexed ankle), movement duration (increased), dynamic range of motion at the knee (reduced), and extension torques at the hip (increased). CONCLUSION: The alterations in joint dynamics among patients with knee OA may have revealed an adaptive motor behavior characterized by redistributing the load from impaired to less-impaired or nonimpaired joints through multijoint dynamics. Two major potential pitfalls of such a movement strategy have subsequently been postulated.

Aged↗
PubMed1994

Impact of joint impairment on longitudinal disability in elderly persons.

Recent longitudinal data indicating that arthritis is a major contributor to disability in elderly persons are based on self-reported diagnostic information. This longitudinal study included baseline physical examinations of joints of 541 persons over age 60. Previous results from a cross-sectional multivariate model of disability in this sample found that joint impairment (and, its absence, arthritis pain) explained a significant proportion of variance in overall disability. We have retested this model using generalized estimation equations (GEE) analysis to estimate the effect of joint impairment and arthritis pain on baseline and Year 2 disability. Findings indicate that baseline joint impairment contributes substantially to longitudinal disability. If direct measures of baseline joint impairment are unavailable, concurrent self-reported arthritis pain also predicts longitudinal disability well. These findings indicate that longitudinal studies should monitor arthritis pain and that symptomatic arthritis is a risk factor for future disability.

Activities of Daily Living↗
PubMed1994

Cost containment: the Middle East. Saudi Arabia.

The 1970s and early 1980s saw the phenomenal growth and development of healthcare services in Saudi Arabia. This growth was unique in that it took place in a country that lacked basic infrastructure and trained personnel, but had recently acquired great wealth. Developments that took hundreds of years to occur in other countries took only 20 yrs to attain in Saudi Arabia. This growth posed unique challenges and required novel solutions. Recently, the country has had to cope with a drastic decrease in oil revenue, as well as cutbacks in healthcare funding. Now that the basic foundations of a national healthcare service have been constructed, it remains to be seen whether gains can be consolidated and steady progress made as more and more Saudi nationals take over and run their own public and private healthcare services.

Cost Control↗
PubMed1994

Outcome prediction for the individual patient in the ICU.

A very difficult clinical problem facing surgeons is knowing when further treatment is futile and no longer appropriate in a patient who has developed severe complications after surgery and is being treated in an intensive care unit. It is now possible to prolong the process of dying among such patients. This results in unnecessary pain and loss of dignity for the patient, anguish and distress for the patient's relatives and is dehumanizing for the clinical and nursing staff. It has also tremendous implications in the use of limited health care resources. A computer model designed to aid this process has to have the following properties: it must reflect the dynamic pathophysiological process and be able to predict death with extreme accuracy and early in the clinical course. The Riyadh algorithm uses computerised dynamic trend analysis of daily organ failure scores (APACHE II score corrected for the number and duration of organ failures), noting the rate of change in score relative to that of the previous day and an absolute threshold to predict death has been developed for this purpose. The algorithm was developed by tracking the daily scores of 200 IUC patients until their death or discharge from the intensive care unit. It was subsequently validated perspectively on 831 patients. During the validation process, the clinicians were blinded to the predictions. There wer 290 deaths and the program predicted 109 deaths (38% of all deaths) with no false-positive predictions. Forty percent of the predictions were made within 48 h in the ICU and 74% within a week.(ABSTRACT TRUNCATED AT 250 WORDS)

Cost of Illness↗
PubMed1993

A randomized, controlled trial of arthroscopic surgery versus closed-needle joint lavage for patients with osteoarthritis of the knee.

OBJECTIVE: To compare arthroscopic surgery and closed-needle joint lavage for patients with non-end-stage osteoarthritis (OA) of the knee under controlled, experimental conditions. METHODS: Thirty-two subjects who met specific clinical, radiologic, medical, and rehabilitation criteria were randomized to receive arthroscopic surgery (n = 18) or joint lavage (n = 14). Outcome measures evaluated at baseline and at 3 and 12 months of followup included 3 standard clinical parameters, self-reported pain and functional status (by the Arthritis Impact Measurement Scales), 50-foot walk time, 2 global scales, and direct and indirect medical costs. RESULTS: At 3 months of followup, there were no significant between-group differences in pain, self-reported and observed functional status, and patient and "blinded" physician global assessments. The arthroscopic procedure cost $3,840 more than did closed-needle joint lavage. After 1 year, there were no between-group differences in medication costs, utilization of medical services, or indirect costs related to employment or use of household help. After 1 year, 44% of subjects who underwent arthroscopy reported improvement and 58% of subjects who underwent joint lavage improved. Patients with tears of the anterior two-thirds of the medial meniscus or any lateral meniscus tear had a higher probability of improvement (by "blinded" physician assessment) after arthroscopic surgery (0.63) than did patients with other intraarticular pathology (0.20). CONCLUSION: The search for and removal of soft tissue abnormalities via arthroscopic surgery does not appear justified for all patients with non-end-stage OA of the knee who fail to respond to conservative therapy, but it may be beneficial for certain subgroups.

Aged↗
PubMed1993

Assessment of clinical competence of medical students by using standardized patients with musculoskeletal problems.

OBJECTIVE: To assess medical students' clinical competence in addressing musculoskeletal problems. METHODS: Nineteen junior medical students completed 2 standardized patient-based tests structured to capture their clinical decisions from undiagnosed chief complaint to management. RESULTS: No student approached the highest possible score on either test, and the students as a group received less than half the possible points on 5 important aspects of diagnostic reasoning. CONCLUSION: Standardized patient-based tests can be structured to provide enlightening information about medical students' clinical competence with regard to musculoskeletal problems.

Arthritis, Rheumatoid↗
PubMed1993

The critical path method in stroke rehabilitation: lessons from an experiment in cost containment and outcome improvement.

This study tested the effects of a project network technique called the Critical Path Method (CPM) on the costs and outcomes of inpatient team stroke rehabilitation. On admission to a large, academic, inpatient rehabilitation hospital adults who had a recent (< 120 days) stroke were randomly assigned to receive rehabilitation services from a team trained in CPM (N = 53) or from usual care teams (N = 68). Results showed no significant difference between groups in length of stay, hospital charges, or functional status at discharge. CPM may be effective in patient care services that are less influenced by specialization, professional issues, and external regulation and in settings where patient outcomes are relatively fixed and predictable, and medical care is integrated across institutions.

Activities of Daily Living↗
PubMed1993

Joint impairment and self-reported disability in elderly persons.

Recent findings indicating that arthritis is a major contributor to disability in elderly persons are based on self-reported diagnostic information. We conducted physical examinations of the joints at baseline on 541 older persons. We then tested a multivariate model of total/generic disability which included respondent group, demographic and chronic disease variables (joint impairment and comorbid conditions), arthritis pain, and psychological status. Hierarchical multiple regression found that the model explained 55 percent (adjusted R2 = .55) of the variance in baseline disability with joint impairment accounting for 15 percent (change in R2 = .15) of the variance. When joint impairment was removed from the model, arthritis pain worked well as a surrogate. Together, these findings strongly support the importance of musculoskeletal disease in explaining disability in the elderly population.

Activities of Daily Living↗
PubMed1993

Rehabilitation and biomechanics.

In this review, we discuss large epidemiologic and focused clinical and laboratory studies published over the past year that advanced our current knowledge of the physical and functional impairments, societal handicaps, and disability related to the rheumatic diseases. Studies of rehabilitative methods appropriate for patients with a variety of rheumatic and musculoskeletal disorders are presented.

Arthritis↗