Social capital: a novel platform for understanding social determinants of health in systemic lupus erythematosus.

OBJECTIVE: The objective of this paper is to introduce the concept of social capital as a unique and distinct entity from the traditional psychosocial factors of social support, depressive symptoms, and self-efficacy in systemic lupus erythematosus (SLE) patients, and to evaluate how social capital varies in an SLE sample according to demographic, clinical, and psychosocial variables. METHODS: In a cross-sectional study, SLE patients completed the Adapted Social Capital Assessment Tool (A-SCAT), which measures cognitive and structural social capital. Patients also completed measures of social support, depressive symptoms, and SLE self-efficacy. Correlations were evaluated between social capital scores and demographic, clinical, and psychosocial variables. RESULTS: We recruited 89 patients (mean age: 39 ± 15 years old, 83 (93): female; mean SLEDAI: 4; mean SLICC 1). The mean A-SCAT score was 34 ± 15 (normal: 0-71); higher scores were associated with female sex, older age, higher education, Caucasian race, and non-Medicaid insurance (p ≤ 0.03 for all); associations were attributable to structural social capital. Social capital was not associated with depressive symptoms, self-efficacy, or affectionate and interaction social support, but was associated with informational and tangible social support (r = 0.39, r = 0.26, respectively, p ≤ 0.02). There were no associations between SLEDAI and SLICC and social capital, social support, and depressive symptoms. CONCLUSIONS: Social capital is a novel construct that, like other traditional psychosocial measures, addresses aspects of SLE not reflected by markers of disease activity. Social capital, however, is distinct from traditional psychosocial measures and offers a new platform on which ideas of social connectedness can broaden our understanding of health and chronic illness.

A pilot study of office-based spirometry in patients with systemic lupus erythematosus.

BACKGROUND: Although pulmonary involvement is common in systemic lupus erythematosus (SLE), its effects on healthy lifestyle physical activity and its association with fatigue have not been well characterized. The goals of this study were to describe pulmonary function measured by office-based spirometry in patients with SLE and to compare spirometry with physical activity and systemic fatigue. METHODS: During an office visit, 49 patients with SLE completed spirometry assessing: a) forced expiratory volume in 1 s (FEV(1), a measure of airway patency and responsiveness); b) forced vital capacity (FVC, a measure of lung volume); and c) maximum voluntary ventilation (MVV, a measure of volume of air moved during rapid breathing) which has been hypothesized to be decreased in SLE due to muscle fatigue. Patients also performed a 2-min corridor walking test and completed self-reported questionnaires measuring weekly physical activity and systemic fatigue. RESULTS: Mean age was 45 years, 45 (92%) were women, mean SLEDAI and SLICC scores were 2.8 and 1.0, respectively. Some 24 patients had a smoking history, and 15 had a history of SLE-related pleuritis, which was not active at enrollment. FEV(1) and FVC were 96% of predicted, but MVV was only 55% of predicted. The distance walked during the corridor test was similar to that of patients with other chronic diseases; however, self-reported physical activity was less than recommended by national guidelines. There were no associations between spirometry values and history of pleuritis, other pulmonary diagnoses, or smoking (p > .10 for all comparisons), however, better FEV(1) (p = .04) and better FVC (p = .04) were associated with more self-reported activity and better FEV(1) (p = .03) was associated with longer distance walked during the corridor test. Most patients reported marked systemic fatigue; however, there were no associations between spirometry values and fatigue scores (p > .10 for all comparisons). CONCLUSIONS: MVV was markedly diminished, which supports the hypothesis that SLE may be associated with respiratory muscle fatigue during rapid breathing. MVV was not associated with mild-to-moderate patient-directed physical activity; however, lower FEV(1) and FVC were associated with less self-reported and performance-based physical activity.

Perceptions and measurements of physical activity in patients with systemic lupus erythematosus.

Promoting physical activity should be a priority for patients with systemic lupus erythematosus (SLE) because a sedentary lifestyle compounds patients' already disproportionately high risk for cardiovascular events and other adverse health outcomes. The objectives of this pilot study were to assess physical activity in 50 patients with SLE and to compare activity levels with clinical and psychosocial variables, such as fatigue, depressive symptoms, and social support and stress. Patients were asked open-ended questions about physical activity, and responses were coded according to Grounded Theory. Patients then completed the Paffenbarger Physical Activity and Exercise Index, a survey of lifestyle energy expenditure reported in kilocalories/week, performed a 2-minute walk test according to a standard protocol, and completed questionnaires measuring fatigue, depressive symptoms and social support and stress. Most patients (92%) were women, had a mean age of 45 years, and did not have extensive SLE. In response to open-ended questions, patients reported they avoided physical activity because they did not want to exacerbate SLE in the short term. However, if they could overcome initial hurdles, 46 patients (92%) thought physical activity ultimately would improve SLE symptoms. Walking was the preferred activity and 45 (90%) thought they could walk more. According to the Paffenbarger Index, mean energy expenditure was 1466 ± 1366 kilocalories/week and mean time spent in moderate-intensity activity was 132 ± 222 min/week. In total, 18 patients (36%) and 14 patients (28%) met physical activity goals for these values, respectively. Mean distance walked during the 2-minute test was 149 ± 28 m, equivalent to two blocks, which is similar to reports for stable patients with other chronic diseases. Patients with more social stress and more fatigue reported less physical activity. We conclude that the proportion of patients meeting physical activity goals was low; however, patients performed well on a standard walking test. Most patients believed physical activity provided long-term benefits for SLE and that they could be more physically active.

How do cancer patients who try to take control of their disease differ from those who do not?

The objective of this study was to compare patients who do and do not describe their coping strategies as attempts to control their cancer. This was a cross-sectional study of adult, oncology outpatients from an urban medical centre diagnosed 6-24 months previously. Using open-ended questions, we asked participants if they tried to 'control' their cancer or situation. If 'yes', how? If 'no', how had they 'dealt with' it? The Hospital Anxiety and Depression Scale (HAD) measured anxiety and depression. The Mental Adjustment to Cancer Scale (MAC) assessed six coping styles. Of the 44 participants, 57% were female. The mean age was 57 years. Eighteen (41%) said they used control strategies (control-yes), 11 (25%) said they did not (control-no), and 15 (34%) gave unclear responses (control-unclear). Participants cited 97 different coping strategies that were grouped into proactive (e.g. lifestyle changes) and reactive strategies (e.g. stoic behaviour). In comparing these groups, the control-yes group was more likely to be younger (P = 0.0001), live with other(s) (P = 0.003), be confident of being cured (P = 0.006), have greater 'fighting spirit' on the MAC (P = 0.04) and use more proactive strategies (P = 0.0001). The conclusion of this study is that cancer patients use many coping strategies, but those who think of them as methods of control are younger and more confident of being cured, and use more proactive strategies.

Self-efficacy, depressive symptoms, and patients' expectations predict outcomes in asthma.

BACKGROUND: Certain psychosocial variables are relatively unexplored as possible predictors of asthma outcomes. OBJECTIVE: To determine if asthma self-efficacy, depressive symptoms, and unrealistic expectations predict urgent care use and change in health-related quality of life measured by the Asthma Quality of Life Questionnaire and the SF-36 during 2 years. RESEARCH DESIGN: Prospective cohort study in a primary care internal medicine practice at a tertiary care center in New York City. PATIENTS: Adults with moderate asthma who were fluent in either English or Spanish. MEASUREMENTS: At enrollment patients were interviewed in-person and completed a series of questionnaires including the Asthma Quality of Life Questionnaire (AQLQ), the SF-36, the Asthma Self-efficacy Scale, the Geriatric Depression Scale, and open-ended questions regarding their expectations of treatment. Patients also completed the AQLQ and SF-36 at various time intervals throughout the study and were interviewed by telephone every 3 months to record recent hospitalizations, emergency department visits and nonroutine office visits for asthma. RESULTS: A total of 224 patients were followed for a mean of 23.8 months. In hierarchical analysis, independent predictors of lower AQLQ scores were less self-efficacy, more depressive symptoms, expecting to be cured of asthma, requiring methylxanthines, being Hispanic or black, and having difficult or very difficult access to asthma care (all at P <0.05). Similar predictors were found for lower SF-36 scores. Another outcome, use of urgent care, was required by 60% of patients during the study period. Predictors of using urgent care were having more depressive symptoms, expecting a cure, being female, requiring oral beta-agonists, and having a history of prior hospitalizations for asthma (all at P <0.05). CONCLUSIONS: Less asthma self-efficacy, more depressive symptoms, and unrealistic expectations predict worse asthma outcomes. These relatively unexplored patient-centered variables in asthma are potentially modifiable and may offer new ways to intervene to improve asthma outcomes.

Smoking cessation following CT screening for early detection of lung cancer.

BACKGROUND: This study was conducted to assess the impact of lung cancer screening participation on smoking cessation. METHODS: Individuals (n = 134) who reported active smoking at the time of enrollment in our Early Lung Cancer Action Program (ELCAP) completed a brief, follow-up telephone interview assessing any changes in smoking patterns following lung cancer screening. Using logistic regression, we estimated the probability of decreasing or quitting smoking using each enrollee's background information and computed tomography (CT) scan results. RESULTS: Most survey respondents (74%) agreed that participation in the ELCAP increased their motivation for quitting smoking. In terms of self-reported changes in smoking behavior, 31 (23%) reported that they had quit and 35 (27%) decreased their smoking patterns. Several significant covariates of smoking cessation were identified: perceived benefit of quitting (OR 4.02), cancer anxiety (OR 2.49), younger age (OR 2.47), and abnormal CT finding (1.97). CONCLUSIONS: Our analyses suggest that low-dose helical CT scanning may serve as a strong catalyst for smoking cessation and that delivery of effective smoking cessation interventions along with CT scanning represents a potential opportunity to increase the overall cancer prevention benefit of lung cancer screening.

Patients' expectations of knee surgery.

BACKGROUND: Patients' expectations of medical care are linked to their requests for treatment and to their assessments of outcome and satisfaction. Our goals were to measure patients" preoperative expectations of knee surgery and to develop and test patient-derived knee expectations surveys. METHODS: An initial sample of 377 patients (mean age, 54.6 18.2 years; 52% women) was enrolled in the survey-development phase. One hundred and sixty-one (43%) of these patients subsequently underwent total knee arthroplasty; seventy-five (20%), cruciate ligament repair; eighty-five (23%), meniscal surgery; and fifty-six (15%), surgery for another knee condition. Preoperatively, these patients were asked open-ended questions about their expectations of knee surgery. Their responses were grouped with use of qualitative research techniques to generate categories of expectations. Categories were transformed into specific questions and were formatted into two draft surveys, one for patients undergoing total knee arthroplasty and one for patients undergoing other surgical procedures on the knee. A second sample of 163 patients (mean age, 55.1 17.5 years; 49% women) was enrolled in the survey-testing phase, and they completed the draft surveys on two separate occasions to establish test-retest reliability. Items were selected for the final surveys if they were cited by 5% of the patients, if they represented important functional changes resulting from surgery, or if they represented potentially unrealistic expectations. All selected items fulfilled reliability criteria, defined as a kappa (or weighted kappa) value of 0.4, or were deemed to be clinically relevant by a panel of orthopaedic surgeons. RESULTS: From the survey-development phase, a total of fifty-two categories of expectations were discerned; they included both anticipated items such as pain relief and improvement in walking ability and unanticipated items such as improving psychological well-being. Expectations varied by diagnosis and patient characteristics, including functional status. Two final surveys were generated: the seventeen-item Hospital for Special Surgery Knee Replacement Expectations Survey and the twenty-item Hospital for Special Surgery Knee Surgery Expectations Survey. Each required less than five minutes to complete. CONCLUSIONS: Patients have multiple expectations of knee surgery in the areas of symptom relief and improvement of physical and psychosocial function, and these expectations vary according to the diagnosis. We developed two valid and reliable surveys that can be used preoperatively to direct patient education and shared decision-making and to provide a framework for setting reasonable goals. Reexamining patients' responses postoperatively could provide a way to assess fulfillment of expectations, which is a crucial patient-derived measure of outcome and satisfaction.

Comparing discriminative validity between a disease-specific and a general health scale in patients with moderate asthma.

Health-related quality of life scales such as the Asthma Quality of Life Questionnaire and the Medical Outcomes Study Short-form General Health Survey SF-36 have become important measures of health status in clinical asthma trials. The discriminative properties of these scales, however, have not been extensively evaluated and compared. The purposes of this study were to assess and compare scale and discriminative properties of the Asthma Quality of Life Questionnaire (AQLQ) and the SF-36 in a group of patients with moderate asthma using a patient-rated global measure of disease activity as the criterion variable. Patients were interviewed in-person with a series of questionnaires including the AQLQ and the SF-36, and were also asked the global question "How active is your asthma now?" with possible responses of "extremely," "very," "moderately," "mildly" or "not active." Discriminative properties were determined using receiver operating characteristic (ROC) curves with responses to the global question as the criterion variable and mean domain scale scores as the independent variables. Relative validities for the AQLQ and SF-36 domains were also compared. A total of 230 patients, mean age of 41 years, were enrolled. Scores were lower and ranges were narrower for the AQLQ compared to the SF-36. In general, the AQLQ and the SF-36 were highly correlated, with r = 0.69 for the AQLQ overall score and the SF-36 Physical Component Summary (PCS) score. According to ROC analyses, both scales had excellent discriminative properties; however the area under the ROC curve was higher for the AQLQ overall score (0.81) than for the PCS (0.75). When ranked according to ROC area, the symptoms domain (0.83) had the greatest area under the ROC curve, followed by the emotional (0.76) and activities (0.76) domains of the AQLQ. However, in some cases, the area under the curve was less for an AQLQ domain (for example, 0.71 for the environmental domain) than for SF-36 domains (for example, 0.75 for the role physical, and 0.75 for the social domain). Similarly, the AQLQ overall had a higher relative validity (5.2) compared to the PCS (2.2), and the symptoms domain of the AQLQ had the highest relative validity (6.0). Thus, both the Asthma Quality of Life Questionnaire and the SF-36 were able to characterize patients with moderate asthma in our cross-sectional study. In addition, both scales had strong discriminative properties when assessed with a global patient rating of current disease activity.

Effects of depressive symptoms on health-related quality of life in asthma patients.

OBJECTIVE: To assess the effects of depressive symptoms on asthma patients' reports of functional status and health-related quality of life. DESIGN: Cross-sectional study. SETTING: Primary care internal medicine practice at a tertiary care center in New York City. PATIENTS: We studied 230 outpatients between the ages of 18 and 62 years with moderate asthma. MEASUREMENTS AND MAIN RESULTS: Patients were interviewed in person in English or Spanish with two health-related quality-of-life measures, the disease-specific Asthma Quality of Life Questionnaire (AQLQ) (possible score range, 1 to 7; higher scores reflect better function) and the generic Medical Outcomes Study SF-36 (general population mean is 50 for both the Physical Component Summary [PCS] score and Mental Component Summary [MCS] score). Patients also completed a screen for depressive symptoms, the Geriatric Depression Scale (GDS), and a global question regarding current disease activity. Stepwise multivariate analyses were conducted with the AQLQ and SF-36 scores as the dependent variables and depressive symptoms, comorbidity, asthma, and demographic characteristics as independent variables. The mean age of patients was 41 +/- SD 11 years and 83% were women. The mean GDS score was 11 +/- SD 8 (possible range, 0 to 30; higher scores reflect more depressive symptoms), and a large percentage of patients, 45%, scored above the threshold considered positive for depression screening. Compared with patients with a negative screen for depressive symptoms, patients with a positive screen had worse composite AQLQ scores (3.9 +/- SD 1.3 vs 2.8 +/- SD 0.8, P <.0001) and worse PCS scores (40 +/- SD 11 vs 34 +/- SD 8, P <.0001) and worse MCS scores (48 +/- SD 11 vs 32 +/- SD 10, P <.0001) scores. In stepwise analyses, current asthma activity and GDS scores had the greatest effects on patient-reported health-related quality of life, accounting for 36% and 11% of the variance, respectively, for the composite AQLQ, and 11% and 38% of the variance, respectively, for the MCS in multivariate analyses. CONCLUSIONS: Nearly half of asthma patients in this study had a positive screen for depressive symptoms. Asthma patients with more depressive symptoms reported worse health-related quality of life than asthma patients with similar disease activity but fewer depressive symptoms. Given the new emphasis on functional status and health-related quality of life measured by disease-specific and general health scales, we conclude that psychological status indicators should also be considered when patient-derived measures are used to assess outcomes in asthma.

Adaptations made by rheumatoid arthritis patients to continue working: a pilot study of workplace challenges and successful adaptations.

OBJECTIVES: The goals of this pilot study were to use qualitative research techniques in a group of currently employed patients with rheumatoid arthritis (RA) to develop categories of challenges encountered in maintaining employment and categories of successful adaptations made to continue working; and to identify obstacles considered to be persistent threats to continued employment. METHODS: Patients were interviewed by telephone with a questionnaire composed of structured-response format and open-ended response format questions focusing on specific challenges and adaptations in the workplace. RESULTS: Of the 22 patients interviewed, 96% were women, mean age was 50 years, 84% were college graduates, and the majority had light physical job demands and high autonomy over their work and hours worked. Patients encountered diverse challenges, such as fatigue, pain, typing, writing, physical requirements, maintaining a pleasant disposition, working overtime, traveling for business, commuting, being on time, not being able to choose rest periods, and environmental issues. Patients also made multiple adaptations to continue working, the most helpful being changing job or altering career path (36%), altering work hours (32%), using more disease-modifying antirheumatic drugs (27%), using car service (23%), sleeping more (18%), and working at home (14%). Patients were not at all confident in their ability to continue working because of RA, and perceived the following persistent threats to continued employment: fatigue (45%), not being able to use hands (45%), not being able to choose rest periods (27%), and commuting problems (18%). In addition, patients confronted psychological stresses, such as dealing with coworkers and supervisors and balancing job and personal roles. These challenges and adaptations included unfavorable work-related occurrences, or "negative work-role events." CONCLUSIONS: Seemingly successfully employed patients with RA faced multiple challenges and made major adaptations to maintain employment and still perceived their employment to be in jeopardy because of RA. The findings of this study have important implications for screening patients at risk for negative work-role events and for possible work-related and social support interventions aimed at preserving employment.

Impact of new guidelines on physicians' ordering of preoperative tests.

OBJECTIVE: To compare the number of preoperative tests ordered for elective ambulatory surgery patients during the 2 years before and the 2 years after the establishment of new hospital testing guidelines. MEASUREMENTS: The patterns of preoperative testing by surgeons and a medical consultant during the 2 years before and the 2 years after the establishment of new guidelines at one orthopedic hospital were reviewed. All tests ordered preoperatively were determined by review of medical records. Preoperative medical histories, physical examinations, and comorbidities were obtained according to a protocol by the medical consultant (author). Perioperative complications were determined by review of intraoperative and postoperative events, which also were recorded according to a protocol. MAIN RESULTS: A total of 640 patients were enrolled, 361 before and 279 after the new guidelines. The mean number of tests decreased from 8.0 before to 5.6 after the new guidelines ( p =.0001) and the percentage decrease for individual tests varied from 23% to 44%. Except for patients with more comorbidity and patients receiving general anesthesia, there were decreases across all patient groups. In multivariate analyses only time of surgery (before or after new guidelines), age, and type of surgery remained statistically significant ( p =.0001 for all comparisons). Despite decreases in surgeons' ordering of tests, the medical consultant did not order more tests after the new guidelines ( p =.60) The majority of patients had no untoward events intraoperatively and postoperatively throughout the study period, with only 6% overall requiring admission to the hospital after surgery, mainly for reasons not related to abnormal tests. Savings from charges totaled $34,000 for the patients in the study. CONCLUSIONS: Although there was variable compliance among physicians, new hospital guidelines were effective in reducing preoperative testing and did not result in increases in untoward perioperative events or in test ordering by the medical consultant.

Patients' expectations and satisfaction with total hip arthroplasty.

Although there have been many studies focusing on the increasingly important assessment of patients' satisfaction, few studies have specifically addressed this tissue for total hip arthroplasty (THA). The goals of this study were to measure patients' satisfaction with THA and to evaluate the relationships of expectations and outcome to patients' satisfaction. A total of 180 patients were surveyed 2 to 3 years after THA about their experiences with THA. Patients cited 45 different expectations, which were grouped into five categories reflecting improvement in pain, walking, psychological state, essential activities, and nonessential activities. Overall, 89% of patients were satisfied with the results of surgery. Lower rates of satisfaction were found in patients who had a better preoperative condition (as measured by the surgeons with The Hospital for Special Surgery Hip Scale), in patients who expected improvement in nonessential activities, and in patients who reported worse postoperative condition (as measured by self-assessment with the Hip Rating Questionnaire and the Medical Outcomes Study Short-form General Health Survey). Patients were also asked how they came to THA. Nearly 50% of patients were first referred to an orthopaedist by family or friends or based on their own knowledge. Seventy-four percent either had subsequently referred others for THA or would have done so if they knew someone with hip pain. This study demonstrates that satisfaction with THA is a complex phenomenon, affected by expectations, outcome, and what patients know about the procedure from their community network. A better understanding of THA satisfaction will enable better future selection of patients and an additional dimension of outcome, both of which are important to patients and payers.

Indications for total hip and total knee arthroplasties. Results of orthopaedic surveys.

A lack of consensus regarding the indications for total hip arthroplasty (THA) and total knee arthroplasty (TKA) has been cited as one reason for the variations in the rates of THA and TKA across the United States. The purposes of this study were to survey orthopaedists in a specific geographic area (New York City) regarding the candidacy of patients with osteoarthritis for THA or TKA and to compare indications for THA between orthopaedists at two academic medical centers, The Hospital for Special Surgery in the United States and McGill University in Canada. Orthopaedists were sent mail surveys asking about indications, factors affecting outcomes, and factors that might modify decisions for surgery. Approximately 45% of orthopaedists who performed THA and TKA in New York City in 1992 completed the surveys. Although there were wide variations among surgeons, most surgeons required at least severe pain daily, rest pain several days per week, transfer pain either several days per week (THA) or daily (TKA), and destruction of most of the joint space on radiograph. Younger age, comorbidity, technical difficulties, and lack of motivation modified the decision against surgery, whereas the desire to be independent and return to work swayed the decision for surgery. Most surgeons rated that patients with severe pain, osteoarthritis, or rheumatoid arthritis would have a high likelihood of an excellent outcome, whereas those with comorbidity and certain technical factors would have only a moderate likelihood of an excellent outcome. In the U.S.-Canadian survey of THA, in which more than 90% of surgeons responded, Canadian surgeons tended to require more frequent pain and use of assistive devices for walking. Although there was a majority of opinion for several indications, there was no clear consensus among surgeons regarding the indications for THA and TKA. Possible explanations for this are that isolated indications are not as important as integrating and weighing several indications and that the patient's desire to proceed with THA or TKA is an important driving force in the decision to operate.

Does recollection error threaten the validity of cross-sectional studies of effectiveness?

New cross-sectional studies have been designed to evaluate therapeutic effectiveness of medical and surgical treatments. The extent to which error in recollection may threaten the validity of conclusions reached in these studies has not been determined. The purpose of this research was to evaluate the impact of recollection error by comparing patients' prospectively acquired reports about their condition before total hip replacement with their recollections of their preoperative condition obtained several years after surgery. A total of 104 patients prospectively completed the Hip Rating Questionnaire (HRQ), a valid, reproducible, responsive, disease-specific scale composed of four domains (pain, walking, function, and impact of hip arthritis on overall health). These same patients then completed the HRQ several years after surgery by recalling their preoperative condition. Current postoperative condition was also obtained several years after surgery with the HRQ. Patient characteristics include: 55% were women, mean age was 67 years, 90% had osteoarthritis, 78% had no prognostically significant comorbid disease, and the mean time interval between surgery and recall was 2.5 years. Comparison of prospective and recalled responses with the weighted kappa and intraclass correlation coefficients showed poor to fair agreement in three domains, and moderate agreement in the fourth domain. Overall, the directions of the recollection errors were toward patients' recalling more pain, better walking, better function, and worse impact of hip arthritis on health than they reported before surgery. When the data were stratified to determine if there were systematic biases among major patient subgroups, there were discrepancies in the percentage of patients within each subgroup who had recollection error for the different domains, as well as differences in the magnitudes and directions of the recollection errors. These results indicate that relying on patients' recollections does not provide an accurate measure of preoperative state, and that attempting to adjust data is not feasible because the directions and magnitudes of recollection error vary for major subgroups of patients. In addition, when outcome was assessed using postoperative HRQ responses, the cross-sectional data overestimated the effectiveness of total hip replacement in 68% of patients. It is concluded that cross-sectional data do not accurately portray baseline preintervention condition and therefore can lead to overestimating, as in this instance, or to underestimating effectiveness.

Methyl methacrylate levels in the breast milk of a patient after total hip arthroplasty.

Blood levels of methyl methacrylate (MMA) are known to be transiently elevated in patients having undergone total hip arthroplasty using cement fixation. However, it is not known whether MMA is present in the breast milk of lactating women after this procedure. The authors studied an otherwise healthy lactating 29-year-old mother 5 months postpartum who had undergone total hip arthroplasty because of walking limitations due to congenital hip dysplasia. Less than 0.0005 micrograms/mL of MMA was found in her breast milk 36 hours after the procedure. If the negative findings in this case can be confirmed in a larger trial, the current practice of discontinuing breast-feeding after arthroplasty may be reconsidered.

Geographic variations in the rates of elective total hip and knee arthroplasties among Medicare beneficiaries in the United States.

We analyzed the variations in the rates of elective total hip and total knee arthroplasties for 1988 in the United States to determine whether the rates correlated with the numbers of surgeons. There were 56,204 total hip arthroplasties and 68,491 total knee arthroplasties, performed in the home states of the patients among all of the Medicare beneficiaries. Medicare beneficiaries include most people who are more than sixty-five years old in the United States and a small proportion of younger people who are eligible for Medicare for other reasons. Seventy-nine per cent of the patients who had had a total hip arthroplasty and 89 per cent of those who had had a total knee arthroplasty had been managed with the operation because of osteoarthrosis. Both operations were most common in the seventy to seventy-four-year age-group. We calculated the rate of operations per 100 beneficiaries for each state and age-adjusted the results. Across all of the states, bilateral procedures constituted 1.6 per cent of the total hip arthroplasties and 4.8 per cent of the total knee arthroplasties. The in-hospital rates of mortality were 0.72 per cent for total hip arthroplasties and 0.45 per cent for total knee arthroplasties. The destinations after discharge from the hospital were similar for the two groups of patients, with more than 65 per cent of the patients being discharged directly to their homes. There were no significant differences among states in terms of the length of stay in the hospital or reimbursement of the hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbial community structure and biomass estimates of a methanogenic Antarctic Lake ecosystem as determined by phospholipid analyses.

Phospholipid analyses were performed on water column particulate and sediment samples from Ace Lake, a meromictic lake in the Vestfold Hills, Antarctica, to estimate the viable microbial biomass and community structure in the lake. In the water column, methanogenic bacterial phospholipids were present below 17 m in depth at concentrations which converted to a biomass of between 1 and 7×10(8) cells/liter. Methanogenic biomass in the sediment ranged from 17.7×10(9) cells/g dry weight of sediment at the surface to 0.1×10(9) cells/g dry weight at 2 m in depth. This relatively high methanogenic biomass implies that current microbial degradation of organic carbon in Ace Lake sediments may occur at extremely slow rates. Total microbial biomass increased from 4.4×10(8) cells/ liter at 2 m in depth to 19.4×10(8) cells/liter at 23 m, near the bottom of the water column. Total nonarchaebacterial biomass decreased from 4.2 ×10(9) cells/g dry weight in the surface sediment (1/4 the biomass of methanogens) to 0.06×10(8) cells/g dry weight at 2 m in depth in the sediment. Phospholipid fatty acid profiles showed that microeukaryotes were the major microbial group present in the oxylimnion of the lake, while bacteria dominated the lower, anoxic zone. Sulfate-reducing bacteria (SRB) comprised 25% of the microbial population at 23 m in depth in the water column particulates and were present in the surface sediment but to a lesser extent. Biomass estimates and community structure of the Ace Lake eco-system are discussed in relation to previously measured metabolic rates for this and other antarctic and temperate ecosystems. This is the first instance, to our knowledge, in which the viable biomass of methanogenic and SRB have been estimated for an antarctic microbial community.

A model for physicians' therapeutic decision making.

We explored physician's cognitive processes when making therapeutic decisions in a complex situation in which more than one treatment option is acceptable. Eighteen internists were presented with three hypothetical cases of patients with coronary artery disease and were asked to explain their treatment decisions. Based on process tracing, we characterized their method of therapeutic decision making. We found that physicians use a three-stage process that we call focal composite analysis: (1) selection of a few facts (focal points) and evaluation of each fact individually with respect to treatment options; (2) reassessment of the value of the focal points with respect to each other and unification of the case; and (3) summation of the values of the focal points to make the final decision. Using this model, we predicted physicians' actual treatment decisions in 96% of the hypothetical cases. Further analysis revealed a wide variety of focal points chosen overall, with most physicians choosing different focal points in each case. Of a total of 32 focal points chosen in three cases, only two focal points were predictors of the physicians' actual treatment choices. We conclude that in the complex problem considered here physicians use a staged process of choosing and evaluating information to make therapeutic choices.

A method for the separation and characterization of archaebacterial signature ether lipids.

A reproducible high performance liquid chromatography (HPLC) method for the separation of diethers and tetraethers isolated from archaebacterial phospholipids is reported. Fourier transform infrared spectroscopy was used for structural confirmation of these signature lipids. A mixture of tetraethers from a thermoacidophilic archaebacteria was resolved into three major components by the normal phase separation. These components were differentiated by Fourier self-deconvolution of infrared spectra. The application of the HPLC technique to environmental samples may provide an accurate assessment of archaebacterial biomass in various microbial communities.

C15, C20, and C25 isoprenoid homologues in glycerol diether phospholipids of methanogenic archaebacteria.

The glycerol diether phospholipids of 25 monocultures of methanogenic bacteria were isolated and degraded with hydriodic acid. The resulting alkyl iodides were converted to acetate esters and alcohols which were examined using capillary gas-liquid chromatography. The presence of C20 phytanol was observed in accordance with previous studies. Soft fragmentation by chemical ionization mass spectrometry combined with selected ion monitoring enabled the detection, for the first time, of C15 and C25 isoprenologues as components of the diether phospholipids in several strains.