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Biomedical subjects

M H Liang

Publications and source records attributed to M H Liang.

At least 73 records · Page 4Linked to original sources
PubMed1997

Patients' preferences and their relationship with satisfaction following carpal tunnel release.

Patients' preferences for specific health outcomes in carpal tunnel syndrome (CTS) and their association with demographic factors and satisfaction with the results of surgery after 6 months were evaluated. Two hundred fifty subjects with CTS and enrolled in a prospective community-based cohort study in Maine completed a preference questionnaire before surgery. Patients were asked to specify the single most important reason they decided to undergo surgery and to rate the importance of improvement in 10 areas, including lessening of specific symptoms and improvement in specific functional states related to CTS. The single most important reason for CTS patients to have surgery was relief of night pain (37%), followed by relief of numbness (21%) and relief of daytime pain (13%). When patients were asked to rate the importance of obtaining relief from specific symptoms and improvement in specific functional states, relief of numbness received the highest rating, with 94% of the patients answering that it was extremely or very important. Workers' compensation recipients, patients with less than a college level of education, and patients with more severe symptoms and functional impairment at baseline assigned higher importance to symptom relief and functional improvement. Controlling for other predictors, higher preference for improved strength was associated with lower satisfaction with the results of the surgery at 6 months. Most CTS patients undergoing surgery have realistic preferences for health outcomes that are influenced by demographic and clinical characteristics; however, physicians should pay attention to unrealistic preferences that might influence patients' satisfaction with surgical results.

Carpal Tunnel Syndrome↗
PubMed1997

Silicone breast implants and systemic rheumatic disease. Some smoke but little fire to date.

For over 20 years silicone breast implants have been used for cosmetic and breast reconstruction purposes. They have been recently banned by the American Food and Drug Administration other than for reconstruction or in the setting of a study. Complications of rupture, leaking, bleeding, capsular thickening and contracture are acknowledged but the potential of silicone implants in causing classic rheumatic diseases or a new syndrome has caused much controversy; there are millions of dollars at stake in legal suits. The biological plausibility of silicone breast implants causing disease is not without merit. The epidemiological evidence linking the two are reviewed. There is considerable concern as to whether there will ever be a definitive study of the question.

Breast Implants↗
PubMed1996

Measurement properties of a self-administered outcome measure in lumbar spinal stenosis.

STUDY DESIGN: The measurement properties and validity of a newly developed patient questionnaire for the assessment of patients with lumbar spinal stenosis was tested in an ongoing prospective multicenter observational study of patients undergoing decompressive surgery in three teaching hospitals. OBJECTIVE: The goal of the study was to develop a short, self-administered questionnaire on symptom severity, physical functional status, and patient satisfaction. SUMMARY OF BACKGROUND DATA: The measure is intended to complement existing generic measures of spinal-related disability and health status. The questionnaire includes three scales with seven questions on symptom severity, five on physical function, and six on satisfaction. METHODS: The internal consistency of the scales was assessed with Cronbach's coefficient alpha on cross-sectional data from 193 patients before surgery. The test-retest reliability was assessed on data from a random sample of 23 patients using Spearman's rank correlation coefficient. The responsiveness was assessed on 130 patients with 6-month follow-up data using the standardized response mean. RESULTS: The test-retest reliability of the scales ranged from 0.82 to 0.96, the internal consistency from 0.64 to 0.92, and the responsiveness from 0.96 to 1.07. The direction, statistical significance, and strength of hypothesized relationships with external criteria were as expected. CONCLUSIONS: This short self-administered spinal stenosis measure is reproducible, internally consistent, valid, and highly responsive. It can be used to complement generic instruments in outcome assessment of patients with lumbar spinal stenosis.

Aged↗
PubMed1996

The North American spine society lumbar spine outcome assessment Instrument: reliability and validity tests.

STUDY DESIGN: A cross-sectional study of a convenience sample of lumbar spine patients, with a subsample followed for retest reliability. OBJECTIVES: To assess the instrument's reliability, validity, and acceptability to patients. SUMMARY OF BACKGROUND DATA: Patients with eight diagnoses, four before surgery and four after surgery, were recruited from six orthopedic practices to test the questionnaire. METHODS: One hundred sixty-seven patients were approached through the physician's office, yielding 136 usable questionnaires (84%) and 24-hour retests on 64 patients. RESULTS: The questionnaire took about 20 minutes to administer and was acceptable to patients. The lumbar spine pain and disability and neurogenic symptoms subscales discriminated among patient groups as hypothesized and showed significantly better scores for patients independently judged successful by their physicians after surgery. Test-retest reliability and internal reliability were high (range, 0.85-0.97). Sample sizes of 20-37 would be needed to detect a 20% difference between two groups (alpha, 0.05; beta, 0.20). CONCLUSIONS: The questionnaire should be considered for monitoring of individual patient's progress in treatment and for clinical trials.

Adult↗
PubMed1996

Classics in Spine. Surgery literature revisited.

STUDY DESIGN: This article reviews the criteria for evaluating the quality of clinical trials. OBJECTIVES: To outline the current methodologic standards by which the validity of controlled trials need to be evaluated. SUMMARY OF BACKGROUND DATA: Weber's study, published in 1983 in Spine, is the only randomized trial comparing surgery and conservative management of sciatica in herniated lumbar discs. METHODS: Weber's article is revisited to illustrate basic principles in the design of clinical trials. RESULTS: Weber's study is a classic in spine surgery and has changed thinking regarding the benefit of surgery in sciatica related to herniated lumbar discs. However, the authors found potentially critical flaws in this study: a large number of crossovers, inadequate sample size, and insensitive outcome measurements. CONCLUSIONS: A randomized, controlled trial is the most rigorous way to evaluate health intervention. Despite the difficulties of performing such studies, investigators should use the most appropriate scientific methodology.

Clinical Trials as Topic↗
PubMed1996

Seven- to 10-year outcome of decompressive surgery for degenerative lumbar spinal stenosis.

STUDY DESIGN: Retrospective review and prospective follow-up of 88 patients who had decompressive laminectomy with or without fusion from 1983 to 1986. OBJECTIVE: To determine the 7- to 10-year outcome of surgery for degenerative lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: There is limited information on the impact of surgery for lumbar spinal stenosis on symptoms, walking ability, and satisfaction, as well as reoperation. METHODS: Patients completed standardized questionnaires in 1993 that included items about reoperations, back pain, leg pain, walking capacity, and satisfaction with surgery. Associations between preoperative demographic and clinical variables and outcomes 7 to 10 years after surgery were evaluated in univariate and multivariate analyses. RESULTS: Average preoperative age was 69 years and eight patients received fusion. Of 88 patients in the original cohort, 20 (23%) were deceased and 20 (23%) had undergone reoperation by 7- to 10-year follow-up. Fifty-five patients answered questionnaires. Average duration of follow-up was 8.1 years. Thirty-three percent of the respondents had severe back pain at follow-up, 53% were unable to walk two blocks, and 75% were satisfied with the results of surgery. The severity of current spine-related symptoms was a stronger correlate of physical functional status at the time of follow-up than age or nonspinal comorbid conditions. CONCLUSIONS: Seven to 10 years after decompressive surgery for spinal stenosis, 23% of patients had undergone reoperation and 33% of respondents had severe back pain. Despite a high prevalence of nonspinal problems in this elderly cohort, spinal symptoms were the most important correlate of reduced functional status.

Aged↗
PubMed1996

Hair dye use and the risk of developing systemic lupus erythematosus.

OBJECTIVE: To investigate the role of hair dye use in the etiology of systemic lupus erythematosus (SLE). METHODS: Participants included 106,391 women enrolled in the Nurses' Health Study, a prospective cohort study. The subjects were ages 30-55 years in 1976, and were free from SLE and any other connective tissue disease at the time of enrollment. In 1976, 1978, 1980, and 1982, subjects were classified as never-users or ever-users of permanent hair dye, based on self-report. Incidence rates of SLE meeting American College of Rheumatology classification criteria were ascertained and confirmed by chart review. RESULTS: Compared with never-users of permanent hair dye, the age-adjusted relative risks (RR) for the development of SLE among ever-users (n = 85 cases) was 0.96 (95% confidence interval [95% CI] 0.63-1.47). Duration of hair dye use was not related to risk of SLE. Women with 15 or more years of use had no increased risk (RR = 0.92, 95% CI 0.46-1.83). There was no relationship between frequency of use or time since first use and risk of SLE. The results were similar when less stringent criteria for SLE were used. CONCLUSION: We found no evidence that permanent hair dye use, age at first use, frequency of use, or duration of use is associated with the development of SLE.

Adult↗
PubMed1996

Interpretation of change scores in ordinal clinical scales and health status measures: the whole may not equal the sum of the parts.

The objective of this study was to analyze the problem of interpreting change scores of ordinal health status measures for clinical research or practice. Methods used included exploration of the generation of change scores in the physical ability scale of the SF-36, one of the most widely used generic health status instruments. Resulting data are presented as the ranking of items according to baseline score; a percentage of patients with severe difficulty and Rasch analysis provided the same rank order of item difficulty. On the interval scale provided by the Rasch model a concentration of items reflecting moderate difficulty occurred. This "inflates" numerical gains for patients with moderate disability compared to patients with very severe or minor physical disability. Calibration of change scores using patient perception of the level of change in function showed important variation of numerical gains with baseline. We conclude that numerically equal gains may differ in their meaning depending on baseline health status. It is recommended that distribution of baseline health status measures and distribution of responders by baseline status be reported in evaluative studies.

Data Collection↗
PubMed1996

Total hip arthroplasty: use and select complications in the US Medicare population.

Use and outcomes of primary total hip arthroplasty among US Medicare recipients more than 65 years of age were investigated by means of physician and hospital claims for a 5% random sample during 1986 through 1989. Cases involving hip fracture or evidence of existing orthopedic devices in the hip were omitted. Use rates were higher for women than for men and were substantially lower for Blacks than Whites. Major complications (death, further hip surgery, infection pulmonary embolism) were uncommon. These data document the frequent use of total hip arthroplasty, and confirm the rarity of serious adverse outcomes. Further studies should investigate the lower use of total hip arthroplasty among Blacks.

Black or African American↗
PubMed1996

Use of misoprostol in the elderly: is the expense justified?

Misoprostol is a prostaglandin E1 analogue which reduces both gastric ulcerations and clinically important bleeding in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs). Economic evaluations of prophylactic use of misoprostol with NSAIDs differ in their conclusions mainly because of different assumptions regarding the absolute risk reduction of symptomatic ulcers. Assuming a conservative estimate of the absolute risk reduction based on new effectiveness data, all studies would have concluded that misoprostol prophylaxis results in net costs in the general population of NSAID users. However, in the elderly with a clearly increased risk of gastrointestinal (GI) lesions and ulcer complications, and an increased hospitalisation rate, misoprostol may be cost saving. Also, in the elderly the gain in quality of life seems to offset the uncertain reduction in quality of life due to the adverse effects of misoprostol. However, the suggestion that misoprostol prophylaxis in the elderly is cost effective or cost saving needs to be confirmed in further studies.

Aged↗
PubMed1996

Female hormone therapy and the risk of developing or exacerbating systemic lupus erythematosus or rheumatoid arthritis.

Clinical and animal studies suggest a role for female hormones in preventing or ameliorating rheumatoid arthritis and, on the other hand, increasing the risk for systemic lupus erythematosus. However, the body of the epidemiological studies do not support these observations except for one study showing that hormonal replacement therapy increases the risk of developing systemic lupus-erythematosus. Counseling of women on the use of oral contraceptives or postmenopausal hormones should include a discussion of these risks and benefits in addition to the risks of cardiovascular disease, uterine and breast cancer, and osteoporosis.

Adult↗
PubMed1995

Silicone breast implants and the risk of connective-tissue diseases and symptoms.

BACKGROUND: Silicone breast implants have been linked to a variety of illnesses, the most controversial of which are connective-tissue diseases and symptoms. To study this relation, we analyzed data from 14 years of follow-up of the Nurses' Health Study cohort. METHODS: Women who were free from connective-tissue disease in June 1976 were followed through May 31, 1990, before there was widespread media coverage of the possible association of breast implants and connective-tissue diseases. Information was collected through biennial and supplementary mailed questionnaires and blinded reviews of medical records with the use of standardized criteria. Relative risk, the measure of association, was defined as the incidence rate of connective-tissue disease among women with breast implants divided by the corresponding incidence rate among women without breast implants. RESULTS: Among 87,501 women who were eligible for follow-up, 516 were confirmed as having definite connective-tissue diseases and 1183 as having breast implants (of which 876 were silicone-gel-filled, 170 saline-filled, 67 double-lumen, 14 polyurethane-coated, and 56 of unknown type). The mean (+/- SD) period of follow-up after surgery was 9.9 +/- 6.4 years (range, 1 month to 40.5 years). Three of the patients with definite connective-tissue disease--all had rheumatoid arthritis--had implants (one silicone-gel-filled, one saline-filled, and one double-lumen). The age-adjusted relative risk of a definite connective-tissue disease among women with any type of implant was 0.6 (95 percent confidence interval, 0.2 to 2.0), as compared with women without implants. For women with silicon-gel-filled implants, the comparable relative risk was 0.3 (95 percent confidence interval, 0 to 1.9). The relative risk of self-reported signs or symptoms of connective-tissue disease for women with implants was 1.5 (95 percent confidence interval, 0.9 to 2.4); the risk of having any 1 of 41 signs, symptoms, or laboratory features of connective-tissue disease was 0.7 (95 percent confidence interval, 0.3 to 1.6). CONCLUSIONS: In a large cohort study, we did not find an association between silicone breast implants and connective-tissue diseases, defined according to a variety of standardized criteria, or signs and symptoms of these diseases.

Adult↗
PubMed1995

Clinical correlates of patient satisfaction after laminectomy for degenerative lumbar spinal stenosis.

STUDY DESIGN: Prospective multicenter observational study of the outcome of surgery for degenerative lumbar spinal stenosis. OBJECTIVES: To identify correlates of patient satisfaction with the results of surgery. SUMMARY OF BACKGROUND DATA: Little published information exists on correlates of patient satisfaction after surgery for spinal stenosis. METHODS: Preoperative and 6-month follow-up data for 194 patients were analyzed. Associations between preoperative variables and satisfaction with the results of surgery were examined in univariate and multivariate models. RESULTS: In multiple linear regression models that adjusted for the effects of age, gender, individual surgeon, number of interspaces decompressed, whether a fusion was performed, depression score, and overall level of pain, the predominance of back (as opposed to leg) pain, greater comorbidity, and worse preoperative functional status were associated with lower patient satisfaction. The regression model explained just 15% of the variance in patient satisfaction. CONCLUSIONS: Patients bothered predominantly by back pain preoperatively and those with greater medical comorbidity and functional disability are significantly less satisfied with the results of surgery for degenerative lumbar spinal stenosis.

Aged↗
PubMed1995

Postmenopausal estrogen therapy and the risk for developing systemic lupus erythematosus.

OBJECTIVE: To examine the relation between postmenopausal hormone use and development of systemic lupus erythematosus. DESIGN: Prospective cohort study. SETTING: Nurses' Health Study. PATIENTS: 69,435 women aged 30 to 55 years in 1976 who reported that they had completed menopause and did not have systemic lupus erythematosus or any connective tissue disease were followed every 2 years from 1976 to 1990. These women were classified as never- or ever-(current and past) users of postmenopausal hormones. MEASUREMENTS: Incidence rates of systemic lupus erythematosus and classification criteria from the American College of Rheumatology that were confirmed by chart review. RESULTS: With never-users of postmenopausal hormones as the reference group, age-adjusted relative risks for systemic lupus erythematosus (n = 45 women) were 2.1 (95% CI, 1.1 to 4.0) for ever-users, 2.5 (CI, 1.2 to 5.0) for current users, and 1.8 (CI, 0.8 to 4.1) for past users. A proportional increase in the risk for systemic lupus erythematosus was observed that was related to the duration of use of postmenopausal hormones (test for trend, P = 0.011). CONCLUSIONS: Postmenopausal hormone therapy is associated with an increased risk for developing systemic lupus erythematosus.

Adult↗
PubMed1995

Practical management of osteoarthritis. Integration of pharmacologic and nonpharmacologic measures.

Pharmacotherapy should play an adjunctive role to nonpharmacologic measures in the overall management of patients with symptoms due to osteoarthritis. Patients should be instructed in how to rest or unload involved joints; protect them through appropriate manipulation of their environment and appropriate methods of lifting and bending; and maintain and improve muscle strength and flexibility to ensure joint stability and prevent contractures. In most patients, acetaminophen in doses of up to 4 g/d is preferable to nonsteroidal anti-inflammatory drugs (NSAIDs) as a first-choice agent because of its lower toxicity. If NSAIDs are used, they should be prescribed initially in lower (analgesic) doses. Ibuprofen may be the preferred initial NSAID because it can be given in low doses for short durations, has been associated with lower rates of gastrointestinal tract side effects, and is inexpensive.

Acetaminophen↗
PubMed1995

A self-administered rheumatoid arthritis disease activity index (RADAI) for epidemiologic research. Psychometric properties and correlation with parameters of disease activity.

OBJECTIVE: To examine the psychometric properties and construct validity of a self-administered Rheumatoid Arthritis Disease Activity Index (RADAI). METHODS: Five items of the Rapid Assessment of Disease Activity in Rheumatology (RADAR) questionnaire were aggregated into the RADAI and assessed for their factor loading, internal consistency, and construct validity. RESULTS: In 55 patients with RA, the RADAI had a high internal consistency (Cronbach's alpha = 0.91) and correlated with physician's assessment of disease activity (r = 0.54, P < 0.01), the swollen joint count (r = 0.54, P < 0.01), and the C-reactive protein value (r = 0.43, P < 0.01). CONCLUSION: The RADAI is a highly reliable and valid self-administered measure of disease activity for clinical, health services, and epidemiologic research. Its sensitivity to change in longitudinal studies needs further study.

Adult↗