VF-14 item specific responses in patients undergoing first eye cataract surgery: can the length of the VF-14 be reduced?

AIMS: To report the item specific responses of the VF-14 in a population of patients undergoing cataract surgery in their first eye and to determine whether or not the VF-14 can be reduced without compromising its performance as an index of cataract related visual impairment. METHODS: The item specific responses to the VF-14 were analysed before (771 patients) and 4 months after (552 patients) cataract surgery in one eye to determine if the VF-14 index can be reduced without compromising its performance. Patients studied were selected from a cross sectional longitudinal study of patients undergoing cataract surgery in 72 ophthalmologist's offices located in three metropolitan regions of the United States. RESULTS: Pairwise correlations between items in the VF-14 were all less than 0.6, indicating that no items could be removed solely on the basis of redundancy. 10 items correlated moderately with change in trouble, and 11 correlated moderately with change in satisfaction (r >0.15) at 4 months after cataract extraction. Eleven items demonstrated an effect size >0.4 at 4 months. These 11 items were either important for detecting cataract related functional disability or for quantifying the extent to which cataract impaired function. Additionally, 11 items were needed to detect adequately individuals with functional impairment. Three items (recognising people, cooking, and reading large print) were less responsive to cataract extraction and were more strongly associated with ocular comorbidities. CONCLUSIONS: While previous reports indicate that the VF-14 can be significantly shortened, our analysis only justifies removing three items. While the resulting VF-11 has properties similar to the VF-14, the limited time savings do not justify altering this already validated instrument.

Prevalence and characteristics of individuals with chronic kidney disease in a large health maintenance organization.

This study is designed to estimate the prevalence of and gain further insight into the characteristics of the chronic kidney disease (CKD) population in a large US health maintenance organization (HMO) to better understand the CKD population in the United States overall. Analyses were performed using data from a staff and network model HMO in the southwestern United States with more than 150,000 members per year during 1994 to 1997. The estimated prevalence of CKD in the HMO population varied from 0.4% to 7.1%, depending on the definition of CKD used. Regardless of the definition, CKD was more common in men compared with women and in patients with diabetes mellitus and/or hypertension. Applying the age- and sex-specific prevalence rates in the HMO to the US population in 1990, we estimate there were approximately 9.1 million Americans with at least one elevated sex-specific creatinine (Cr) value and approximately 4.2 million Americans with at least two elevated Cr values separated by 90 days or greater, a more rigorous definition of CKD. From these results, it is apparent that there are a large number of patients in the United States with CKD. Most have not been identified because screening for CKD generally is not performed. Considering the high prevalence of CKD and the high cost and clinical morbidity associated with end-stage renal disease (ESRD), it is clear that CKD is an important public health problem. Early identification of patients with CKD would allow treatment that could slow the progression to ESRD, improve clinical outcomes, and constrain the growth of costs in the ESRD program. The time has come for a structured public and professional educational program to address this serious condition.

Patient outcomes of refractive surgery. The refractive status and vision profile.

PURPOSE: To evaluate the performance of a questionnaire, the Refractive Status and Vision Profile (RSVP), in the assessment of patient outcomes following refractive surgery. SETTING: Patients recruited from 5 refractive surgery practices. METHODS: The RSVP was self-administered by patients before and 2 to 6 months after bilateral refractive surgery. Information on uncorrected visual acuity (UCVA), refractive error, and self-reported satisfaction with vision was also collected. Changes in total RSVP scores and in the scores of RSVP subscales (concern, functioning, driving, symptoms, optical problems, glare, and trouble with corrective lenses) were assessed. The relationship between change in the RSVP and subscale scores was assessed in relation to change in traditional clinical measures. The responsiveness of the RSVP to clinically meaningful changes in patients' vision was measured by calculating its effect size. RESULTS: One hundred seventy-six patients completed baseline and postoperative RSVPs and had bilateral refractive surgery. Postoperatively, 92.0% of patients had a UCVA of 20/40 or better in at least 1 eye. Fifteen percent had some worsening in the total RSVP score, and there was substantial variation in the proportion of patients who had worsening in particular subscale scores, ranging from 7.0% who reported worsening in trouble with corrective lenses to 41.5% who reported worsening in driving. Change in satisfaction with vision following surgery was correlated with change in the overall RSVP and subscale scores but not with change in refractive error. A significant worsening in 3 or more RSVP subscales was independently associated with an almost 6-fold (odds ratio 5.84, 95% confidence interval: 1.88,18.13) likelihood of patient report of dissatisfaction with vision, after adjusting for age, sex, preoperative refractive error, and postoperative UCVA. Low scores (ie, minimal dysfunction) on 2 of the RSVP subscales (physical functioning and optical problems) at baseline were predictive of poor postoperative patient outcomes. The RSVP was very sensitive to the intervention of refractive surgery (effect size of 1.2 to 1.4). CONCLUSIONS: The RSVP was able to detect clinically relevant changes in functional status and quality of life after refractive surgery. Change in the RSVP score was correlated with change in patient report of satisfaction and was predictive of postoperative patient satisfaction. The RSVP provides a valuable new metric to assess outcomes of refractive surgery.

The refractive status and vision profile: a questionnaire to measure vision-related quality of life in persons with refractive error.

OBJECTIVE/BACKGROUND: To describe the Refractive Status and Vision Profile (RSVP), a questionnaire that measures self-reported vision-related health status (symptoms, functioning, expectations, concern) in persons with refractive error. DESIGN: Cross-sectional study by survey. PARTICIPANTS: The RSVP was self-administered by 550 participants with refractive error (or history of refractive surgery) recruited from five refractive surgery practices and one optometric practice. Information on refraction, uncorrected and best-corrected visual acuity, and history of refractive surgery was obtained from physicians' records. METHODS: Internal consistency, test-retest reliability, agreement with global measures of vision (criterion validity), discriminant validity, content validity, and construct validity (associations of scale scores with patient status variables) were assessed using Cronbach's alpha, Spearman rank correlations, factor analysis, and multitrait analysis. OUTCOME MEASURES: Scores on the overall RSVP scale (S) and on eight RSVP subscales (functioning, driving, concern, expectations, symptoms, glare, optical problems, problems with corrective lenses) were calculated based on 42 items. RESULTS: Cronbach's alpha was 0.92 for S and ranged from 0.70 to 0.93 for RSVP subscales, indicating good internal consistency. Satisfaction with vision was more strongly associated with S than with refractive error or with visual acuity. Individuals with more refractive error had significantly lower (worse) scores for S and for subscales concern, functioning, driving, optical problems, and glare. Scores for S and for subscales concern, functioning, optical problems, and driving remained significantly associated with satisfaction with vision after adjustment for age, gender, corrective lens type, and refractive error. CONCLUSIONS: The RSVP measures a range of visual, functional, and psychologic impacts of refractive error that are likely to be important to patients. The RSVP would be a useful tool for evaluating interventions for correction of refractive error and may be useful for assessing refractive surgery candidates in clinical practice.

Methods used to evaluate the quality of evidence underlying the National Kidney Foundation-Dialysis Outcomes Quality Initiative Clinical Practice Guidelines: description, findings, and implications.

This report describes the approach the National Kidney Foundation-Dialysis Outcomes Quality Initiative (NKF-DOQI) used to assess the strength of published evidence pertinent to individual NKF-DOQI Clinical Practice Guidelines, as well as the relationship between that approach and methods used by the US Preventive Services Task Force, the Cochrane Collaboration, and the Agency for Health Care Policy and Research to rate the quality and/or strength of evidence. We also present the results of an analysis of the strength of evidence underlying the NKF-DOQI Guidelines showing that one cannot infer the quality of evidence reported in a study (rated either on a 0-to-1 scale or categorically as excellent, very good, good, fair, or poor) simply by knowing the type of study design used (randomized trial, nonrandomized trial, natural experiment, cohort study, cross-sectional study, case-control study, case report). Issues related to assessment of the strength of evidence underlying a practice guideline opposed to that reported in an individual study are highlighted.

Initial two years of experience with the AAO National Eyecare Outcomes Network (NEON) cataract surgery database.

PURPOSE: To report the results of the first 2 years of experience with an American Academy of Ophthalmology (AAO) cataract surgery registry; to compare patient characteristics, operative procedures, and patient outcomes observed in the registry to those observed in the Cataract PORT study; and to discuss the current shortcomings and potential benefits of a national cataract surgery registry. DESIGN: Observational study of episodes of cataract surgery reported by a self-selected sample of 249 ophthalmologists. PARTICIPANTS: Seven thousand six hundred twenty-six patients undergoing cataract surgery during 1996 and 1997. METHODS: Beginning in January 1996, participation in the AAO cataract surgery registry was offered to all ophthalmologists. Participants could use software or paper data collection forms to submit a common set of data regarding patients' demographics, preoperative ophthalmologic history, physical examination and test results, functional status and symptoms, intraoperative procedures and events, and postoperative outcomes for all patients undergoing first or second eye cataract surgery. Data were transmitted to a central database, where they were aggregated and analyzed. Findings were compared with those observed in the Cataract PORT study, which was conducted in 1991 and 1992. RESULTS: Between January 1, 1996, and February 28, 1998, 249 ophthalmologists submitted data on at least one patient who underwent cataract surgery. A total of 7626 patients undergoing first or second eye surgery were enrolled, with all preoperative, intraoperative, and postoperative data forms submitted for 3342 patients (44%). The preoperative characteristics of patients reported to National Eyecare Outcomes Network (NEON) were similar to those of patients enrolled in the Cataract PORT study except for a higher reported prevalence of ocular comorbidity in NEON patients. Use of retrobulbar anesthesia was reported far less commonly, and use of topical anesthesia, phacoemulsification, and foldable intraocular lenses was reported far more often for NEON than for Cataract PORT study patients. Patient outcomes reported to NEON were similar to those observed in the Cataract PORT study. MAIN OUTCOME MEASURES: Visual acuity, VF-14, Cataract Symptom Score, surgical complications. CONCLUSIONS: During the first 2 years of NEON, ophthalmologist participation in the NEON cataract surgery database was low and consisted of a self-selected and likely nonrepresentative sample of ophthalmologists. The representativeness of patients for whom data were reported is unknown. In addition, complete data were submitted on only a minority of patients who were enrolled. Even so, the preoperative characteristics of patients on whom data were submitted to NEON were similar to those of patients enrolled in the Cataract PORT study. The initial experience with NEON demonstrates that it is technically possible to collect clinical data from, and report aggregated results to, practicing clinicians' offices. In addition, at least some practicing clinicians are willing to spend the time required to participate in the NEON registry. The NEON cataract surgery database thus has the potential to provide a practical means for tracking practice patterns and patient outcomes in real time. If a representative sample of physicians was willing to contribute data systematically and accurately over time, initiatives such as NEON could provide a means for professional societies and physicians to play a leadership role in defining and monitoring quality of care.

The dialysis outcomes quality initiative: history, impact, and prospects.

Rigorously developed clinical practice guidelines have the potential to improve patient outcomes. It is toward that end that the National Kidney Foundation (NKF) launched in March 1995 the Dialysis Outcome Quality Initiative (DOQI), an ambitious effort to develop evidence-based clinical practice guidelines for the care of patients with end-stage renal disease (ESRD). Independent, interdisciplinary work groups conducted a structured review of the content and methodologic rigor of all the published literature pertinent to four selected topics: hemodialysis adequacy, peritoneal dialysis adequacy, vascular access, and anemia. Following expert, organizational, and public review, the guidelines were issued in September and October 1997. An implementation plan that called for widespread dissemination of the guidelines and facilitation of adoption of them has resulted in their broad acceptance and Integration into quality improvement efforts. Additional guidelines on nutrition have recently been completed, while others on bone disease, hypertension, and hyperlipidemia are in various stages of planning or development. A major determinant of poor outcome of maintenance dialysis patients is the debilitated state of many individuals with ESRD at the time that they commence dialysis therapy. The recognition of this problem has stimulated an interest in extending the guidelines to management of patients with less severe renal insufficiency, well before they need renal replacement therapy; and to the early detection of renal insufficiency by a proteinuria and albuminuria risk assessment, detection, and elimination (PARADE) program. What started as an initiative to improve the quality of care of dialysis patients has evolved into a considerably expanded effort to making lives better for all individuals with any level of renal insufficiency.

Beyond survey data: a claims-based analysis of drug use and spending by the elderly.

Previous estimates of Medicare beneficiaries total and out-of-pocket spending on outpatient prescription drugs have largely been based on data from the 1995 Medicare Current Beneficiary Survey and have focused on how expenditures vary among beneficiaries with different demographic characteristics. This paper reports the results of an analysis of prescription claims from 1998 for more than 375,000 elderly persons whose prescription benefit was managed by Merck-Medco Managed Care. In addition to examining how total and out-of-pocket drug spending in a well-insured population varies by age and sex, we report how total and condition-specific drug spending varies for elderly persons with ten common chronic diseases. Our results illustrate the highly skewed nature of prescription drug spending, even among those with drug coverage, and underscore the particularly high cost burden that pharmaceuticals place on elderly people with chronic diseases.

The value of routine preoperative medical testing before cataract surgery. Study of Medical Testing for Cataract Surgery.

BACKGROUND: Routine preoperative medical testing is commonly performed in patients scheduled to undergo cataract surgery, although the value of such testing is uncertain. We performed a study to determine whether routine testing helps reduce the incidence of intraoperative and postoperative medical complications. METHODS: We randomly assigned 19,557 elective cataract operations in 18,189 patients at nine centers to be preceded or not preceded by a standard battery of medical tests (electrocardiography, complete blood count, and measurement of serum levels of electrolytes, urea nitrogen, creatinine, and glucose), in addition to a history taking and physical examination. Adverse medical events and interventions on the day of surgery and during the seven days after surgery were recorded. RESULTS: Medical outcomes were assessed in 9408 patients who underwent 9626 cataract operations that were not preceded by routine testing and in 9411 patients who underwent 9624 operations that were preceded by routine testing. The most frequent medical events in both groups were treatment for hypertension and arrhythmia (principally bradycardia). The overall rate of complications (intraoperative and postoperative events combined) was the same in the two groups (31.3 events per 1000 operations). There were also no significant differences between the no-testing group and the testing group in the rates of intraoperative events (19.2 and 19.7, respectively, per 1000 operations) and postoperative events (12.6 and 12.1 per 1000 operations). Analyses stratified according to age, sex, race, physical status (according to the American Society of Anesthesiologists classification), and medical history revealed no benefit of routine testing. CONCLUSIONS: Routine medical testing before cataract surgery does not measurably increase the safety of the surgery.

Can restrictions on reimbursement for anti-ulcer drugs decrease Medicaid pharmacy costs without increasing hospitalizations?

OBJECTIVE: To examine the impact of a policy restricting reimbursement for Medicaid anti-ulcer drugs on anti-ulcer drug use and peptic-related hospitalizations. DATA SOURCES/STUDY SETTING: In addition to U.S. Census Bureau data, all of the following from Florida: Medicaid anti-ulcer drug claims data, 1989-1993; Medicaid eligibility data, 1989-1993; and acute care nonfederal hospital discharge abstract data (Medicaid and non-Medicaid), 1989-1993. STUDY DESIGN: In this observational study, a Poisson multiple regression model was used to compare changes, after policy implementation, in Medicaid reimbursement for prescription anti-ulcer drugs as well as hospitalization rates between pre- and post-implementation periods in Medicaid versus non-Medicaid patients hospitalized with peptic ulcer disease. PRINCIPAL FINDINGS: Following policy implementation, the rate of Medicaid reimbursement for anti-ulcer drugs decreased 33 percent (p < .001). No associated increase occurred in the rate of Medicaid peptic-related hospitalizations. CONCLUSIONS: Florida's policy restricting Medicaid reimbursement for anti-ulcer drugs was associated with a substantial reduction in outpatient anti-ulcer drug utilization without any significant increase in the rate of hospitalization for peptic-related conditions.

The importance of performance evaluation in implementation of the Dialysis Outcomes Quality Initiative Guidelines.

To determine the extent to which actual practices become more consistent over time with those advocated in Dialysis Outcomes Quality Initiative Guidelines, clinical performance measures (CPMs) that are based on the DOQI Guidelines will need to be developed and implemented. CPMs also can be used to evaluate the effectiveness of interventions that are undertaken to promote compliance with specific Guideline recommendations, to validate DOQI Guidelines that were based in whole or in part on expert opinion, and to protect against erosion of the quality of care delivered to end-stage renal disease patients that could occur as a result of economic pressures. To achieve these goals, CPMs must be valid, reliable, and practical to use. A federally sponsored effort to develop such CPMs is currently underway. This report presents an overview of CPMs and the challenges involved in developing technically sound specifications for CPMs that are based on DOQI guidelines.

Profiling assisted reproductive technology: outcomes and quality of infertility management.

OBJECTIVE: To critically appraise the content of the American Society for Reproductive Medicine (ASRM)/Society for Reproductive Technology (SART) Registry. DESIGN: English-language literature review. PATIENT(S): Women undergoing treatment with assisted reproductive technology (ART). INTERVENTION(S): Current ART treatments, including IVF, GIFT, zygote intrafollopian transfer (ZIFT), oocyte micromanipulation, and cryopreserved embryo transfers. MAIN OUTCOME MEASURE(S): Compliance with clinical practice guidelines, and casemix-adjusted rates of live delivery, clinical pregnancy, ectopic pregnancy, miscarriage, birth defects, implantation, fertilization, and retrieval. RESULT(S): Outcomes should be adjusted for variation in patient characteristics known to affect prognosis, including maternal age, the duration of infertility, the presumed cause(s) of infertility, the patient's prior history of treatment for infertility, and diethylstilbestrol exposure. Outcome rates should be reported using the patient as the denominator, as well as cycle, retrieval, and transfer. The statistical significance of observed differences in events rates should be indicated. Because widely accepted clinical practice guidelines related to performance of ART procedures are not available, compliance with practice guidelines cannot currently be assessed. CONCLUSION(S): Reports based on ASRM/SART Registry data can be enhanced by refined casemix adjustment, assessing outcome rates per patient, as well as per component of ART procedure, and by providing an indication of the statistical significance of observed differences in event rates. In addition, a critical appraisal of available evidence related to particular aspects of infertility management would help clarify the areas in which there is an evidentiary basis for formulation of practice guidelines, as well as topics requiring additional clinical research.

Pharmacoeconomic analysis of 3 treatment strategies for cytomegalovirus retinitis in patients with AIDS.

A decision-analytical simulation model was constructed to perform a pharmacoeconomic analysis of the following 3 treatment strategies for previously untreated cytomegalovirus (CMV) retinitis in patients with AIDS: (i) intravenous foscarnet (IVF) for induction and maintenance therapy; (ii) intravenous ganciclovir (IVG) for induction and maintenance therapy; and (iii) intravenous ganciclovir for induction therapy, followed by oral ganciclovir for maintenance therapy (IVG-ORG). Patients who experienced significant adverse effects during, or who failed, initial therapy were switched once to one of the other 2 treatments. The model was used to estimate the direct medical cost (from the perspective of a public payer), survival, and survival adjusted for disutility because of lost vision, for each strategy in the first year following treatment initiation. The expected first-year costs of treatment initiated with IVF, IVG and IVG-ORG were $US47,918, $US38,817 and $US32,036 (1994 values), respectively, while expected first-year survival was 41 weeks, 35 weeks and 35 weeks, respectively. The incremental cost per incremental year of survival using IVF was $US78,000 versus IVG and $US138,000 versus IVG-ORG before adjustment for lost vision, and $US93,000 versus IVG and $US166,000 versus IVG-ORG after adjustment for lost vision. About 23% of the cost of the IVG treatment strategy was attributable to treatment-related adverse events, compared with 14% of the cost of IVF and 16% of the cost of IVG-ORG. Because of the high failure rate with IVG-ORG, initial treatment with IVG-ORG frequently led to switching to another treatment. Only 27% of the costs associated with the IVG-ORG treatment strategy were in fact attributable to the cost of induction and maintenance therapy prior to a switch to alternative treatment. In this analysis, initial treatment with IVG-ORG was the least costly approach for treating CMV retinitis in patients with AIDS. Initial treatment with IVF resulted in slightly longer survival adjusted for vision-related quality of life. New treatments for AIDS may reduce the survival benefit of initial treatment with IVF.

Patient characteristics associated with diagnostic imaging evaluation of persistent low back problems.

STUDY DESIGN: Post hoc analysis of data from the National Low Back Pain Study, a prospective observational multicenter study of patients referred for the evaluation and treatment of persistent low back problems. OBJECTIVE: To identify patient characteristics associated with use of particular diagnostic imaging examinations in patients with persistent low back problems. SUMMARY OF BACKGROUND DATA: The Agency for Health Care Policy and Research clinical practice guidelines on low back problems suggest that the use of particular diagnostic imaging tests for a given patient should be based on specific characteristics of that patient. METHODS: Use of diagnostic imaging examinations in 2,374 patients with persistent low back problems who were enrolled in the National Low Back Pain Study from 1986 to 1991 was analyzed. Stepwise logistic regression was used to identify patient characteristics that distinguish between enrollees who underwent particular imaging studies. RESULTS: Characteristics that distinguished patients who had undergone magnetic resonance imaging from those who had received only lumbo-sacral spine radiographs included higher socioeconomic status, greater resource use in the preceding 12 months, more functional impairment, presence of sciatica, and presence of neurologic signs/symptoms suggestive of nerve root compromise. Suspected soft tissue involvement was characteristic of enrollees who had undergone magnetic resonance imaging, whereas suspected structural involvement characterized patients who received noncontrast computed tomography. Only nonclinical factors, such as higher annual household income, disability compensation, and male gender distinguished enrollees who had undergone both magnetic resonance imaging and computed tomography-myelography from those who received only computed tomography-myelography. CONCLUSION: Particular patient socioeconomic and clinical characteristics are associated with receipt of specific imaging studies in evaluation of persistent low back problems.

Preference values for visual states in patients planning to undergo cataract surgery.

To assess how preference values that cataract surgery patients assign to their preoperative visual states relate to visual acuity and problems in specific aspects of daily life, the authors interviewed 47 patients scheduled to have cataract surgery. Using a rating-scale technique with a scale from 0 (death) to 1 (excellent health), the patients had a mean preference value of 0.68 for their preoperative vision. Patients' preference values for their preoperative vision were more closely related to problems in specific aspects of daily life (especially feelings of depression and problems interacting with people) than to visual acuity in the operative eye, better eye, or worse eye, or a weighted average of visual acuities in both eyes. These results provide a rationale for relying more on patients' views about the effects of visual impairment than on measures of visual acuity when assessing the need for cataract surgery.

Persistent low back pain in patients suspected of having herniated nucleus pulposus: radiologic predictors of functional outcome--implications for treatment selection.

PURPOSE: To assess the relationship between imaging findings, therapy, and functional outcome in patients with persistent low back pain who are suspected of having herniated nucleus pulposus. MATERIALS AND METHODS: Data collected during a multicenter, longitudinal study were retrospectively analyzed (n = 1,084). Multivariate regression was used to determine the association between imaging findings, therapy, and functional outcome. The patient outcome measure was disability days: the number of days the patient was unable to perform work-related activities. RESULTS: In patients with at least one normal advanced (imaging other than plain radiography) diagnostic study or with an unconfirmed diagnosis of herniated nucleus pulposus, outcome at 2-year follow-up was no better in patients who were treated than in those who were not. In patients with only abnormal advanced imaging results or with a concordant diagnosis based on clinical and imaging findings, outcome was better in patients who underwent surgery than in those treated nonsurgically. Patients with a free fragment, protrusion, or extrusion that was treated surgically had fewer disability days than patients treated nonsurgically. CONCLUSION: Advanced diagnostic imaging studies can play an important role in treatment selection in patients with persistent low back pain who are suspected of having herniated nucleus pulposus.

International applicability of the VF-14. An index of visual function in patients with cataracts.

PURPOSE: There is increased recognition that a rigorous approach to functional assessment should complement the assessment of clinical status. The authors compare the reliability, validity, and responsiveness to clinical change of a visual function index (VF-14) in non-U.S. and in U.S. patients with cataracts. DESIGN: An observational longitudinal study was performed. PARTICIPANTS: One thousand four hundred seven first eye cataract surgery patients were recruited in four international sites: Manitoba (Canada), Denmark, Barcelona (Spain), and the United States. INTERVENTION: Patients were evaluated before cataract surgery and at a 4-month postoperative follow-up visit. Patients completed the preoperative interview and the clinical examination (766 in the United States, 152 in Manitoba, 291 in Denmark, and 198 in Barcelona), and 91.3% of those (1284) also completed the 4-month postoperative follow-up interview and were evaluated postoperatively by an ophthalmologist. MAIN OUTCOME MEASURES: The authors used the following measures: the visual function index (VF-14), the Sickness Impact Profile (SIP), global measures of patients' trouble and satisfaction with vision, and best-corrected visual acuity (VA) in each eye. RESULTS: The VF-14 showed a high internal consistency reliability level in all sites (Cronbach's alpha coefficients > or = 0.84). Correlation of preoperative visual function index scores with the Vision-Related SIP was strong (r = -0.68 in non-U.S. and r = -0.57 in U.S. patients) and with VA in the eye with better vision was moderate (r = 0.40 and r = 0.27, respectively), the pattern of relationships being very similar among U.S. and non-U.S. patients. In patients with only first-eye surgery who reported that their initial trouble with vision had improved, the amount of change in visual function as assessed by the VF-14 (effect size) was large (1.01 for the non-U.S. patients and 1.17 for the U.S. patients). CONCLUSIONS: The non-U.S. versions of the visual function index (VF-14) analyzed are as reliable, valid, and responsive to clinical change as the original U.S. version. These versions are appropriate for international studies of cataract patients outcomes and possibly in routine clinical practice.

Trends in diagnostic imaging for low back pain: has MR imaging been a substitute or add-on?

PURPOSE: To assess whether magnetic resonance (MR) imaging has replaced other diagnostic imaging modalities in the evaluation of persistent low back pain. MATERIALS AND METHODS: Data on diagnostic imaging use in 2,374 adult patients with persistent low back pain in 1987-1990 were analyzed. Multiple logistic regression was used to estimate the annual adjusted odds of lumbosacral spine radiography, MR imaging, unenhanced computed tomography (CT), or CT myelography use. The national cost of diagnostic imaging for persistent low back pain in 1990 relative to 1987 was estimated. RESULTS: The adjusted odds of performing MR imaging in 1990 relative to 1987 was 3.44 (95% confidence interval, 2.63, 4.51), which reflects an estimated increase from 22 studies per 100 enrollees in 1987 to 75 studies per 100 enrollees in 1990. Use of MR imaging in combination with radiography, unenhanced CT, or CT myelography increased. The additional national cost of diagnostic imaging for persistent low back pain in 1990 relative to 1987 was estimated at $70-$176 million. CONCLUSION: MR imaging was used primarily as an add-on rather than a substitute for other imaging modalities in the evaluation of persistent low back pain. Thus, the volume and cost of diagnostic imaging for persistent low back pain have increased.

Atherosclerotic disease in patients undergoing cataract extraction. A nationwide case-control study. The Cataract Patient Outcomes Research Team.

OBJECTIVE: To evaluate the association between cataract extraction and atherosclerosis and its complications. DESIGN: A nationwide case-control study. SETTING AND PARTICIPANTS: Using a 5% random sample of all Medicare beneficiaries, we analyzed Medicare claims data on 60803 persons 65 years of age and older who underwent cataract extraction in 1986 or 1987 and a control group of 63765 persons matched to the cases for age, race, sex, ZIP code, and reason for Medicare entitlement. MAIN OUTCOME MEASURE: Atherosclerosis and atherosclerosis-related disease and procedures were defined by International Classification of Diseases, Ninth Revision, Clinical Modification, codes or by Health Care Financing Administration Common Procedure Classification System (Current Procedural Terminology) codes. The strength of evidence for atherosclerotic disease was categorized on the basis of the types of bills in the Medicare claims file. RESULTS: Odds of atherosclerosis-related morbidity and procedures were higher for cases than for controls. The association decreased with patient age and was strongest in beneficiaries aged 65 to 69 years (odds ratio, 1.30; 95% confidence interval, 1.13-1.48). CONCLUSION: Our findings suggest that there is a weak association between a visually significant cataract requiring surgery and atherosclerosis in the younger elderly.