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Biomedical subjects

G R Cutter

Publications and source records attributed to G R Cutter.

At least 19 recordsLinked to original sources

Benefit of interferon beta-1a on MSFC progression in secondary progressive MS.

BACKGROUND: Interferon beta-1a (IFNbeta-1a, Avonex) is efficacious in relapsing forms of MS. Studies of other IFNbeta preparations in secondary progressive MS (SPMS) yielded conflicting results. This study was undertaken to determine whether IFNbeta-1a slowed disease progression in SP-MS. METHODS: A total of 436 subjects with SPMS and Expanded Disability Status Scale (EDSS) score 3.5 to 6.5 were randomized to receive IFNbeta-1a (60 micro g) or placebo by weekly intramuscular injection for 2 years. The primary outcome measure, used for the first time in a large-scale MS trial, was baseline to month 24 change in the MS Functional Composite (MSFC), comprising quantitative tests of ambulation (Timed 25-Foot Walk), arm function (Nine-Hole Peg Test [9HPT]), and cognition (Paced Auditory Serial Addition Test [PASAT]). RESULTS: Median MSFC Z-score change was reduced 40.4% in IFNbeta-1a subjects (-0.096 vs -0.161 in placebo subjects, p = 0.033), an effect driven mainly by the 9HPT and PASAT. There was no discernible benefit on the EDSS, which in this range principally reflects walking ability. IFNbeta-1a subjects had 33% fewer relapses (p = 0.008). There was significant benefit on eight of 11 MS Quality of Life Inventory subscales. New or enlarging T2-hyperintense brain MRI lesions and gadolinium-enhancing lesions were reduced at months 12 and 24 (both p < 0.001). IFNbeta-1a was well tolerated by the majority of subjects. Neutralizing antibodies developed in 3.3% of IFNbeta-1a-treated subjects. CONCLUSIONS: IFNbeta-1a demonstrated benefit on MSFC progression, relapses, quality of life, and MRI activity in SPMS.

Adjuvants, Immunologic↗

Use of the multiple sclerosis functional composite as an outcome measure in a phase 3 clinical trial.

BACKGROUND: The Multiple Sclerosis Functional Composite (MSFC) is a multidimensional clinical outcome measure that includes quantitative tests of leg function/ambulation (Timed 25-Foot Walk), arm function (9-Hole Peg Test), and cognitive function (Paced Auditory Serial Addition Test). The MSFC is the primary outcome measure in the ongoing multinational phase 3 trial of interferon beta-1a (Avonex) in patients with secondary progressive MS. OBJECTIVE: To assess the practice effects, reliability, and validity of the MSFC clinical outcome measure. DESIGN: Examining technicians underwent formal training using standardized materials. The MSFC was performed according to a standardized protocol. The 436 patients enrolled in the International Multiple Sclerosis Secondary Progressive Avonex Controlled Trial underwent 3 prebaseline MSFC testing sessions before randomization. RESULTS: Practice effects were evident initially for the MSFC but stabilized by the fourth administration. The Paced Auditory Serial Addition Test demonstrated the most prominent practice effects. The reliability of the MSFC was excellent, with an intraclass correlation coefficient for session 3 (final prebaseline session) vs session 4 (baseline) of 0.90. The MSFC at baseline correlated moderately strongly with the Kurtzke Expanded Disability Status Scale. Among the MSFC components, the Timed 25-Foot Walk correlated most closely. Correlations among the 3 MSFC components were weak, suggesting they assess distinct aspects of neurologic function in patients with MS. CONCLUSIONS: The MSFC demonstrated excellent intrarater reliability in this multinational phase 3 trial. Three prebaseline testing sessions were sufficient to compensate for practice effects. The pattern of correlations among the MSFC, its components, and the Kurtzke Expanded Disability Status Scale supported the validity of the MSFC.

Adult↗

The effect of degree of refractive error on hydrogel contact lens-induced complications and patient self-management behaviors.

INTRODUCTION: Although many aspects of hydrogel lens wear have been explored over the last 20 years, little attention has been paid to the role of refractive error magnitude in determining patients' ocular responses or associated contact lens behaviors. METHODS: A cross-sectional study was conducted in 32 optometric and ophthalmologic practices. We enrolled 2161 spherical soft contact lens-wearing patients. High ametropes were defined as those with at least +/- 5.00 D spherical equivalent refractive error in the right eye. Data on current contact lenses, prescribed care regimens, and slit lamp biomicroscopic signs were provided by the eye care practitioners, and information on actual lens care behaviors and attitudes toward contact lens wear were gathered by survey directly from the patients. All differences between high and low ametropes were compared using the chi-square test. RESULTS: Compared with low ametropes, high ametropes were more satisfied with their vision with contact lenses (p < 0.001). More high ametropes wore their lenses on an extended-wear schedule (p = 0.015). Both groups of patients reported a similar degree of lens awareness and lens-associated pain, but fewer high ametropes reported foreign body sensation (p = 0.002). In managing contact lens discomfort, high ametropes were more likely to use an old spare lens (p = 0.01) and more likely to continue wearing their lenses (p = 0.016)--indicators of a propensity for self-management. In response to a damaged lens, high ametropes were less likely to remove both of their lenses (p = 0.002). High ametropes showed more conjunctival staining (p = 0.001) and more corneal scars (p = 0.033). High ametropes also presented with more corneal fluorescein staining (p = 0.001) and more corneal vascularization (p < 0.001). These relations between the degree of ametropia and slit lamp signs of contact lens wear were not significantly affected by daily- vs. extended-wear status. CONCLUSIONS: In summary, practitioners should consider the implications of the patient's degree of ametropia when prescribing contact lenses. These results indicate the need for closer observation and specific advice concerning management of contact lens-related problems when caring for patients with high refractive errors.

Adult↗

Comparison of full-field digital mammography with screen-film mammography for cancer detection: results of 4,945 paired examinations.

PURPOSE: To prospectively compare full-field digital mammography (FFDM) with screen-film mammography (SFM) for cancer detection in a screening population. MATERIALS AND METHODS: At two institutions, 4,945 FFDM examinations were performed in women aged 40 years and older presenting for SFM. Two views of each breast were acquired with each modality. SFM and FFDM images were interpreted independently. Findings detected with either SFM or FFDM were evaluated with additional imaging and, if warranted, biopsy. RESULTS: Patients in the study underwent 152 biopsies, which resulted in the diagnosis of 35 breast cancers. Twenty-two cancers were detected with SFM and 21 with FFDM. Four were interval cancers that became palpable within 1 year of screening and were considered false-negative findings with both modalities. The difference in cancer detection rate was not significant. FFDM had a significantly lower recall rate (11.5%; 568 of 4,945) than SFM (13.8%; 685 of 4,945) (P <.001, McNemar chi(2) model; P <.03, generalized estimating equations model). The positive biopsy rate for findings detected with FFDM (30%; 21 of 69) was higher than that for findings detected with SFM (19%; 22 of 114), but this difference was not significant. CONCLUSION: No difference in cancer detection rate has yet been observed between FFDM and SFM. FFDM has so far led to fewer recalls than SFM.

Biopsy↗

Modelling new enhancing MRI lesion counts in multiple sclerosis.

Magnetic resonance imaging (MRI) has been established as the most relevant paraclinical tool for diagnosing and monitoring multiple sclerosis (MS). In this context, counting the number of new enhancing lesions on monthly MRI scans is widely used as a surrogate marker of MS activity when evaluating the effect of treatments. In this study, we investigated whether parametric models based on mixed Poisson distributions (the Negative Binomial (NB) and the Poisson-Inverse Gaussian (P-IG) distributions) were able to provide adequate fitting of new enhancing lesion counts in MS. We found that the NB model gave good approximations in relapsing-remitting and secondary progressive MS patients not selected for baseline MRI activity, whereas the P-IG distribution modelled better new enhancing lesion counts in relapsing-remitting MS patients selected for baseline activity. This study shows that parametric modelling for MS new enhancing lesion counts is feasible. This approach should provide more targeted tools for the design and the analysis of MRI monitored clinical trials in MS.

Humans↗

Intrarater and interrater reliability of the MS functional composite outcome measure.

OBJECTIVE: To assess practice effects, and intrarater and interrater reliability of the MS functional composite (MSFC) outcome measure. BACKGROUND: To address the poor reliability and insensitivity to change of available MS clinical rating scales, the National MS Society's Clinical Outcomes Assessment Task Force developed the MSFC, a multidimensional quantitative clinical outcome measure that includes tests of leg function/ambulation (Timed 25-Foot Walk), arm function (Nine-Hole Peg Test), and cognitive function (Paced Auditory Serial Addition Test). METHODS: Ten patients with secondary progressive MS underwent six testing sessions over a 2-week period. The MSFC was administered by the same examining technician in the first five sessions and by the other technician in the sixth. Patients were reassessed by both technicians after 6 months (sessions 7 and 8). The MSFC score was calculated as the mean of the Z scores of the three components. A pooled dataset derived from secondary progressive MS patients in the placebo arms of previous clinical trials and natural history studies served as the reference population to standardize scores. RESULTS: Practice effects were evident initially but stabilized by the fourth administration. The intraclass correlation coefficient (ICC) was 0.97 for the MSFC for session 4 versus session 5 (intrarater reliability). The ICC was 0.95 for session 5 versus session 6 (interrater reliability), and was 0.96 for session 7 versus session 8 when patients were reassessed 6 months later. CONCLUSIONS: The MS functional composite (MSFC) outcome measure had excellent intrarater and interrater reliability when standardized procedures were used to train examining technicians and to assess patients. Prebaseline testing sessions should be included in clinical trials employing the MSFC to compensate for practice effects.

Humans↗

New low-contrast vision charts: reliability and test characteristics in patients with multiple sclerosis.

The quantitative assessment of visual function in multiple sclerosis (MS) clinical trials has been limited to Snellen visual acuity. The purpose of this study was to examine the inter-rater reliability and test characteristics of a new visual outcome measure, the Low-Contrast Sloan Letter Charts, in patients with MS and visually-asymptomatic volunteers. Contrast letter acuity scores (letter scores) were measured at each of four contrast levels (100, 5, 1.25 and 0.6%) by two independent raters. Inter-rater agreement was described with the intraclass correlation coefficient (ICC) and comparison of mean scores. Excellent inter-rater agreement (ICC=0.86 - 0.95) was demonstrated at each contrast level among MS patients (n=100) and visually-asymptomatic volunteers (n=33). Average letter scores at the lowest contrast level (0.6%) were highly variable in the MS group, even among patients with visual acuities of 20/20 or better, and among those who required no assistance for ambulation. Low-Contrast Sloan Letter Chart testing is a highly reliable method of visual assessment, and provides information on an aspect of neurologic impairment in MS which is not captured by Snellen visual acuity or ambulation status. This new method demonstrates excellent potential as a visual function outcome measure for future MS clinical trials.

Adolescent↗

Self-reported visual dysfunction in multiple sclerosis: results from the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25).

Visual impairment is one of the most common clinical manifestations of Multiple Sclerosis (MS), and is strongly related to overall health-related quality of life (HRQOL) in MS and other disorders. However, the assessment of vision-specific HRQOL in patients with MS has been limited. The purpose of this study was to examine self-reported visual dysfunction in a clinically heterogeneous MS cohort using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25). The VFQ-25 was administered by telephone interview to a subset of participants in a follow-up study to a phase III trial of interferon beta-1a for relapsing-remitting MS. Mean VFQ-25 composite scores and selected sub-scale scores were significantly lower (worse) among patients in our MS cohort (n=35) compared with a published reference group of patients with no history of chronic eye disease (n= 118). These differences were observed despite a relatively younger age and tighter distribution of binocular visual acuities in the MS cohort Patients with MS in this study thus demonstrated a greater degree of self-reported visual dysfunction, as measured by the VFQ-25, compared with an eye disease-free reference group. The VFQ-25 is a potentially useful measure of vision-specific HRQOL in patients with MS.

Adult↗

Inhaled nitric oxide in premature neonates with severe hypoxaemic respiratory failure: a randomised controlled trial.

BACKGROUND: Inhaled nitric oxide improves oxygenation and lessens the need for extracorporeal-membrane oxygenation in full-term neonates with hypoxaemic respiratory failure and persistent pulmonary hypertension, but potential adverse effects are intracranial haemorrhage and chronic lung disease. We investigated whether low-dose inhaled nitric oxide would improve survival in premature neonates with unresponsive severe hypoxaemic respiratory failure, and would not increase the frequency or severity of intracranial haemorrhage or chronic lung disease. METHODS: We did a double-blind, randomised controlled trial in 12 perinatal centres that provide tertiary care. 80 premature neonates (gestational age < or = 34 weeks) with severe hypoxaemic respiratory failure were randomly assigned inhaled nitric oxide (n=48) or no nitric oxide (n=32, controls). Our primary outcome was survival to discharge. Analysis was by intention to treat. We studied also the rate and severity of intracranial haemorrhage, pulmonary haemorrhage, duration of ventilation, and chronic lung disease at 36 weeks' postconceptional age. FINDINGS: The two groups did not differ for baseline characteristics or severity of disease. Inhaled nitric oxide improved oxygenation after 60 min (p=0.03). Survival at discharge was 52% in the inhaled-nitric-oxide group and 47% in controls (p=0.65). Causes of death were mainly related to extreme prematurity and were similar in the two groups. The two groups did not differ for adverse events or outcomes (intracranial haemorrhage grade 2-4, 28% inhaled nitric oxide and 33% control; pulmonary haemorrhage 13% and 9%; chronic lung disease 60% and 80%). INTERPRETATION: Low-dose inhaled nitric oxide improved oxygenation but did not improve survival in severely hypoxaemic premature neonates. Low-dose nitric oxide in the most critically ill premature neonates does not increase the risk of intracranial haemorrhage, and may decrease risk of chronic lung injury.

Administration, Inhalation↗

Development of a multiple sclerosis functional composite as a clinical trial outcome measure.

The primary clinical outcome measure for evaluating multiple sclerosis in clinical trials has been Kurtzke's expanded disability status scale (EDSS). New therapies appear to favourably impact the course of multiple sclerosis and render continued use of placebo control groups more difficult. Consequently, future trials are likely to compare active treatment groups which will most probably require increased sample sizes in order to detect therapeutic efficacy. Because more responsive outcome measures will be needed for active arm comparison studies, the National Multiple Sclerosis Society's Advisory Committee on Clinical Trials of New Agents in Multiple Sclerosis appointed a Task Force that was charged with developing improved clinical outcome measures. This Task Force acquired contemporary clinical trial and historical multiple sclerosis data for meta-analyses of primary and secondary outcome assessments to provide a basis for recommending a new outcome measure. A composite measure encompassing the major clinical dimensions of arm, leg and cognitive function was identified and termed the multiple sclerosis functional composite (MSFC). The MSFC consists of three objective quantitative tests of neurological function which are easy to administer. Change in this MSFC over the first year of observation predicted subsequent change in the EDSS, suggesting that the MSFC is more sensitive to change than the EDSS. This paper provides details concerning the development and testing of the MSFC.

Clinical Trials as Topic↗

The Multiple Sclerosis Functional Composite Measure (MSFC): an integrated approach to MS clinical outcome assessment. National MS Society Clinical Outcomes Assessment Task Force.

Clinical outcome assessment in Multiple Sclerosis (MS) is challenging due to the diversity and fluctuating nature of MS symptoms. Traditional clinical scales such as the EDSS are inadequate in their assessment of key clinical dimensions of MS (e.g. , cognitive function), and they have psychometric limitations as well. Based on analyses of pooled data from natural history studies and from placebo groups in clinical trials, the National MS Society's Clinical Outcomes Assessment Task Force recently proposed a new multidimensional clinical outcome measure, the MS Functional Composite (MSFC). The MSFC comprises quantitative functional measures of three key clinical dimensions of MS: leg function/ambulation, arm/hand function, and cognitive function. Scores on component measures are converted to standard scores (z-scores), which are averaged to form a single MSFC score. Preliminary analyses confirm that: (1) the three clinical dimensions of the MSFC are relatively independent; (2) the MSFC is sensitive to clinical changes over 1- and 2-year intervals; and (3) the MSFC has acceptable criterion validity (i.e., predicts both concurrent and subsequent EDSS change). The advantages and potential limitations of incorporating quantitative functional outcome measures such as the MSFC into collaborative databases are discussed.

Clinical Trials as Topic↗

Improvement in mammography quality control: 1987-1995.

PURPOSE: To assess possible changes in quality control (QC) practices at mammography sites in the United States. MATERIALS AND METHODS: Mammography site surveys were conducted in 1990, 1992, and 1995 through the Colorado Mammography Advocacy Project (CMAP). Data from mammography sites applying for American College of Radiology (ACR) accreditation were collected between August 1987 and August 1993 through the ACR Mammography Accreditation Program. Data from both of these surveys were analyzed to assess temporal changes in mammography QC practices in the United States between 1987 and 1995. RESULTS: CMAP results indicated statistically significant improvement in medical physicist QC practices between 1990 and 1992 and in technologist QC practices between 1990 and 1995. Improvements in radiologic technologist QC practices coincided with increases in radiologic technologist continuing education in mammography. ACR results indicated statistically significant improvement in technologist QC practices between 1988 and 1992. CONCLUSION: There have been substantial improvements in QC practices at mammography sites in the United States during the past decade.

Chi-Square Distribution↗

A classification system to evaluate weight maintainers, gainers, and losers.

OBJECTIVES: To study natural weight changes and to develop a weight classification system that can identify weight maintainers, gainers, and losers. DESIGN/OUTCOME: A prospective, observational study in which weight changes over five annual measurements were evaluated. In the weight classification system used, changes greater than 5 lb defined weight maintenance, gain, or loss. SUBJECTS/SETTINGS: Subjects were healthy, normal-weight and over weight, men and women (mean age = 44.1 +/- 14.1 years) in the Relationships of Energy, Nutrition, and Obesity to Cardiovascular Disease Risk Study. Prospective data for 385 of the original 508 subjects for whom actual weights were available for each of the 5 years (1985 to 1990) were used to classify and characterize subjects by weight-change categories. STATISTICAL ANALYSES: Cross-tabulations (with chi 2 tests) and hterarchical log-linear analyses (with partial chi 2 tests) to examine the relationships of categorical variables; analyses of variance (with F tests) for continuous measures. RESULTS: Over the 4-year interval, 46% of subjects were classified as maintainers, 34% as gainers, and 20% as losers. Over shorter 1-year epochs, more subjects were maintainers (62%) and fewer subjects were gainers (22%) or losers (16%). Maintainers had fewer and smaller magnitudes of weight fluctuations and showed fewer deleterious changes in health risk factors than gainers. APPLICATIONS: Weight changes of greater than +/-5 lb can classify a person as a weight maintainer, or loser. Although annual weight changes were used in this study, a weight change of more than 5 lb between any two points in time may suggest nonmaintenance of weight or weight instability that needs further evaluation.

Adult↗

Randomized, multicenter trial of inhaled nitric oxide and high-frequency oscillatory ventilation in severe, persistent pulmonary hypertension of the newborn.

BACKGROUND: Although inhaled nitric oxide (iNO) causes selective pulmonary vasodilation and improves oxygenation in newborn infants with persistent pulmonary hypertension, its effects are variable. We hypothesized (1) that the response to iNO therapy is dependent on the primary disease associated with persistent pulmonary hypertension of the newborn (PPHN) and (2) that the combination of high-frequency oscillatory ventilation (HFOV) with iNO would be efficacious in patients for whom either therapy alone had failed. METHODS: To determine the relative roles of iNO and HFOV in the treatment of severe PPHN, we enrolled 205 neonates in a randomized, multicenter clinical trial. Patients were stratified by predominant disease category: respiratory distress syndrome (n = 70), meconium aspiration syndrome (n = 58), idiopathic PPHN or pulmonary hypoplasia (excluding congenital diaphragmatic hernia) ("other": n = 43), and congenital diaphragmatic hernia (n = 34); they were then randomly assigned to treatment with iNO and conventional ventilation or to HFOV without iNO. Treatment failure (partial pressure of arterial oxygen [PaO2] < 60 mm Hg) resulted in crossover to the alternative treatment; treatment failure after crossover led to combination treatment with HFOV plus iNO. Treatment response with the assigned therapy was defined as sustained PaO2 of 60 mm Hg or greater. RESULTS: Baseline oxygenation index and PaO2 were 48 +/- 2 and 41 +/- 1 mm Hg, respectively, during treatment with conventional ventilation. Ninety-eight patients were randomly assigned to initial treatment with HFOV, and 107 patients to iNO. Fifty-three patients (26%) recovered with the initially assigned therapy without crossover (30 with iNO [28%] and 23 with HFOV [23%]; p = 0.33). Within this group, survival was 100% and there were no differences in days of mechanical ventilation, air leak, or supplemental oxygen requirement at 28 days. Of patients whose initial treatment failed, crossover treatment with the alternate therapy was successful in 21% and 14% for iNO and HFOV, respectively (p = not significant). Of 125 patients in whom both treatment strategies failed, 32% responded to combination treatment with HFOV plus iNO. Overall, 123 patients (60%) responded to either treatment alone or combination therapy. By disease category, response rates for HFOV plus iNO in the group with respiratory syndrome and the group with meconium aspiration syndrome were better than for HFOV alone or iNO with conventional ventilation (p < 0.05). Marked differences in outcomes were noted among centers (percent death or treatment with extracorporeal membrane oxygenation = 29% to 75%). CONCLUSIONS: We conclude that treatment with HFOV plus iNO is often more successful than treatment with HFOV or iNO alone in severe PPHN. Differences in responses are partly related to the specific disease associated with PPHN.

Administration, Inhalation↗

The pediatric costs of strategies for minimizing the risk of early-onset group B streptococcal disease.

OBJECTIVE: To estimate the pediatric costs associated with the Centers for Disease Control and Prevention (CDC) guidelines for the management of infants born to mothers receiving intrapartum antimicrobial prophylaxis for prevention of early-onset group B streptococcal disease. METHODS: For an annual United States birth cohort of 3.95 million infants, we estimated the cost of pediatric care provided to full-term asymptomatic infants when pediatricians followed the CDC algorithm for the management of infants exposed to intrapartum antimicrobial prophylaxis under culture-based and risk factor-based maternal care approaches. We calculated the relative contribution of pediatric costs to the total costs of preventing a case of early-onset group B streptococcal sepsis. RESULTS: Total pediatric costs were $41 million for a culture-based approach and $33 million for a risk factor-based approach. Hospital and physician costs accounted for more than 78% of this total. The majority (over 95%) of the pediatric costs were associated with vaginal deliveries. Incorporating pediatric costs into previous cost-effectiveness analyses increased the cost per sepsis case averted by as much as 51% for culture-based strategies and by as much as 112% for risk factor-based strategies. Pediatric costs varied with the average length of stay for full-term infants and with the average cost of a hospital day. CONCLUSION: Substantial pediatric costs are associated with the implementation of an obstetric strategy for minimizing the risk of early-onset group B streptococcal disease. Such costs should be included in future cost-effectiveness analyses of different strategies for minimizing the risk of group B streptococcal disease in newborns.

Algorithms↗

Long-term survival of African Americans in the Coronary Artery Surgery Study (CASS).

OBJECTIVES: This study sought to determine the long-term (> 15 years) outcome of a clinically well characterized cohort of African Americans with known or suspected coronary artery disease (CAD). BACKGROUND: The mortality rate from CAD is higher in African Americans than in whites. An earlier analysis of data from the Coronary Artery Surgery Study (CASS) registry suggested that African American and white patients treated surgically had equal 5-year survival rates. METHODS: Survival data from the CASS registry were analyzed to determine whether 1) African American race is an independent predictor of mortality; and 2) initial therapy is predictive of mortality among African American patients. RESULTS: Overall, 60% of white and 52% of African American patients survived 16 years (p < 0.00001). Multivariate Cox models confirmed that African American race was independently associated with higher mortality in both the medical group (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.11 to 1.63) and the surgical group (HR 1.63, 95% CI 1.19 to 2.23). Initial therapy was not predictive of survival among African American patients (p = 0.81). However, smoking status significantly influenced survival: African Americans who did not smoke experienced significantly improved survival (60% vs. 48% for smokers), which equaled survival for white nonsmokers (61%, p = NS). CONCLUSIONS: In contrast to results from shorter term studies, African Americans experienced higher overall mortality rates than whites over the long term, regardless of the type of initial treatment. Survival among nonsmoking African Americans at 16 years equaled survival among nonsmoking whites.

Adult↗

Evaluating the value of low-vision services.

BACKGROUND: Low-vision care is a widely accepted and valued service provided by many optometrists. As in other areas of health care, evaluation of the outcome of low-vision care is increasingly necessary so it can be properly positioned in the health care delivery system. METHODS: This article reviews the literature relating to the prevalence of low vision, its impact on affected individuals, and how low-vision intervention affects those with visual impairments. This review considers the ways in which the impact of low-vision care has been evaluated. RESULTS: The existing literature demonstrates that low-vision intervention can be highly valued by low-vision patients and can have a significant impact on an individual's daily life and activities. Evaluating this impact is a significant challenge-particularly if the goal is to gauge the outcome of low vision care as broadly as possible. CONCLUSIONS: Evaluation of health-related quality of life is a desirable option for evaluation of outcomes, and the application of quality of life instruments to the visually impaired population is necessary. There remain unresolved issues of optometric research that need to be addressed.

Delivery of Health Care↗