ADHD medications use and risk of mortality and unintentional injuries: a population-based cohort study.

We assessed the association between the use of medications for attention-deficit/hyperactivity disorder (ADHD) and the risk of all-cause mortality and unintentional injuries leading to emergency department (ED) or hospital admission in individuals aged ≤24 years with ADHD. We conducted a population-based retrospective cohort study between 2000 and 2021 using Quebec health administrative data. Individuals were followed from the first ADHD diagnosis or ADHD medication claim until turning 25, death, or study end. Exposure was defined as mutually exclusive episodes of ADHD medication use and/or coverage under the public provincial drug plan (PDP): 1) covered and not treated with ADHD medication; 2) covered and treated with ADHD medication; and 3) not covered under the PDP. The risk of all-cause mortality and unintentional injuries associated with exposure episodes was estimated using multivariable survival analyses. The cohort included n = 217 192 individuals aged 1-24 years with a male to female ratio of close to 2:1. Compared to non-medication use, episodes of ADHD medication use, overall, were associated with reduced all-cause mortality (adjusted hazard ratio, aHR 0.61, 95% CI 0.48-0.76) and unintentional injury leading to ED (0.75, 0.74-0.77) or hospitalisation (0.71, 0.68-0.75). Episodes of stimulants were associated with a lower risk of all-cause mortality and reduced risk of unintentional injuries, while episodes with non-stimulants and with both stimulants and non-stimulants concomitantly were associated with reduced risk of unintentional injuries, but not of all-cause mortality. Although residual confounding cannot be excluded, stimulants may have a protective effect in terms of risk of all-cause mortality and both stimulants and non-stimulants for ADHD may reduce the risk of unintentional injuries. The findings of the current study should inform clinical decision making on the choice of starting a pharmacological treatment for ADHD, when a balance needs to be struck between expected benefits and possible risks.

Economic impact of the use of the National Surgical Quality Improvement Program.

OBJECTIVES: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP®) is a validated, risk-adjusted database for improving the quality and security of surgical care. ACS NSQIP can help participating hospitals target areas that need improvement. The aim of this study was to systematically review the literature analyzing the economic impact of using NSQIP. This paper also provides an estimation of annual cost savings following the implementation of NSQIP and quality improvement (QI) activities in two hospitals in Quebec. METHODS: In June 2018, we searched in seven databases, including PubMed, Embase, and NHSEED for economic evaluations based on NSQIP data. Contextual NSQIP databases from two hospitals were collected and analyzed. A cost analysis was conducted from the hospital care perspective, comparing complication costs before and after 1 year of the implementation of NSQIP and QI activities. The number and the cost of complications are measured. Costs are presented in 2018 Canadian dollars. RESULTS: Out of 1,612 studies, 11 were selected. The level of overall evidence was judged to be of moderate to high quality. In general, data showed that, following the implementation of NSQIP and QI activities, a significant decrease in complications and associated costs was observed, which improved with time. In the cost analysis of contextual data, the reduction in complication costs outweighed the cost of implementing NSQIP. However, this cost analysis did not take into account the costs of QI activities. CONCLUSIONS: NSQIP improves complication rates and associated costs when QI activities are implemented.

Investing in a healthy lifestyle strategy: is it worth it?

OBJECTIVES: In Quebec, various actors fund activities aimed at increasing physical activity, improving eating habits and reducing smoking. The objective was to evaluate how effective does the healthy lifestyle habits promotion (HLHP) strategy need to be to make to offset its costs. METHODS: First, we built the logic model of the HLHP strategy. We then assessed the strategy's total cost as well as the direct health care expenditures associated with lifestyle-related risk factors (smoking, physical inactivity, insufficient intake of fruits and vegetables, obesity and overweight). Finally, we estimated the break-even point beyond which the economic benefits of the HLHP strategy would outweigh its costs. RESULTS: The HLHP strategy cost for 2010-2011 was estimated at $110 million. Direct healthcare expenditures associated with lifestyle-related risk factors were estimated at $4.161 billion. We estimated that 47 % of these expenditures were attributable to these risk factors. CONCLUSIONS: We concluded that the HLHP strategy cost corresponded to 5.6 % of the annual healthcare expenditures attributable to these risk factors. This study compared the economic value of HLHP activities against healthcare expenditures associated with targeted risk factors.

[Effectiveness of psychotherapy compared to pharmacotherapy for the treatment of anxiety and depressive disorders in adults: A literature review]. / Efficacité de la psychothérapie comparativement à la pharmacothérapie dans le traitement des troubles anxieux et dépressifs chez l'adulte : une revue de la littérature.

Introduction In Quebec, mental disorders affect one in five people in their lifetime. Anxiety and depressive disorders are the main common or moderate mental health disorders. They affect both the individuals with the disorder and the people around them and have substantial economic impact. Psychotropic drugs are the treatment option most often proposed to patients presenting with moderate mental health disorders. Psychotherapy is nevertheless a treatment that should be given consideration.Physical and financial access to psychotherapy remains limited because only one third of professionals qualified to offer it practise in the public sector, and the coverage and reimbursement policy for this service is very restricted. In order to improve such coverage, the Ministère de la Santé et des Services sociaux (MSSS) mandated the Institut national d'excellence en santé et en services sociaux (INESSS) to assess the evidence on the effectiveness of psychotherapy compared with those of pharmacotherapy for the treatment of adults with anxiety and depressive disorders.Methods An update of a review of recent and good quality literature was conducted through a review of systematic reviews dealing with psychotherapy compared to pharmacotherapy in the treatment of anxiety and depression in adults. The period covered included 2009 to 2013. The literature search strategy, modelled on that of the reference review, was applied to Medline, Cochrane Library, CINAHL, Web of Science and health technology assessment agencies. Exploration of the grey literature focused on information available on the websites of various health assessment organizations.Results The level of scientific evidence overall was judged to be of moderate to high quality. In general, the data showed no significant difference between psychotherapy and pharmacotherapy in terms of symptoms reduction in patients with moderate anxiety or depressive disorders, indicating comparable effectiveness of these two modes of treatment. However, the benefits of psychotherapy lasted longer after the end of treatment than those of medication. Psychotherapy therefore offers better protection against relapse. Furthermore, the combination of psychotherapy and pharmacotherapy is more effective than psychotherapy alone in severe or chronic cases.Conclusion Psychotherapy appears to be as effective as pharmacotherapy in the treatment of adult patients with moderate anxiety and/or depressive disorders. Moreover, the beneficial effects of psychotherapy last longer after the end of treatment with a lower likelihood of relapse.

Gonioscopic findings associated with a positive dark-room provocative test in narrow angles after laser iridotomy.

PURPOSE: To determine clinical factors and ultrasound biomicroscopic (UBM) findings associated with a positive prone dark-room provocative test (DRPT) in patients with narrow angles after laser peripheral iridotomy (LPI). PATIENTS AND METHODS: Seventeen eyes with a positive DRPT and 18 eyes with a negative DRPT were included in this comparative case series, based on chart review of patients diagnosed with narrow angles persisting after LPI who had undergone clinical evaluation with a 45-minute DRPT and UBM imaging. Subjects with a positive DRPT [an increase of intraocular pressure (IOP) of 6 mm Hg or more] were compared with a negative DRPT control group. Charts were reviewed for age, refraction and gonioscopic examination. UBM measurements obtained included the anterior chamber depth, angle opening distance at 500 µm, angle recess area, anterior chamber angle, trabecular-ciliary process distance, iris thickness, iris-ciliary process distance, height of plateau, and distance of iris-cornea contact. RESULTS: Mean increase in IOP was 11.1±3.5 mm Hg in the positive DRPT group (group A) and 0.9±0.1 mm Hg in the negative DRPT (group B). On indentation gonioscopy, patients in group A had significantly more synechial angle closure of 180 degrees or more (35% vs. 0%, P=0.008), more frequent double-hump sign (59% vs. 11%, P=0.005), and significantly more patients in this group had at least one of these findings, (13/16 vs. 2/15, P=<0.001). Mean age did not differ between groups (P=0.88). There were significantly more women in group B (58% men in group A and 83% women in group B, P=0.01). Mean refraction was +3.41±2.27 D in group A and +2.60±2.06 D in group B (P=0.32). There were no statistically significant differences in any of the UBM parameters between the 2 groups. CONCLUSIONS: A positive DRPT was found in patients presenting a more compromised drainage angle after LPI, due to anterior synechiae and/or an anteriorly positioned ciliary body as shown by the presence of a double-hump sign. DRPT may help identify patients at higher risk of intermittent increases in IOP among those presenting persistent narrow angles after LPI, and indentation gonioscopy remains an important step in evaluating these patients.

The economic value of Quebec's water fluoridation program.

AIM: Dental caries is a major public health problem worldwide, with very significant deleterious consequences for many people. The available data are alarming in Canada and the province of Quebec. The water fluoridation program has been shown to be the most effective means of preventing caries and reducing oral health inequalities. This article analyzes the cost-effectiveness of Quebec's water fluoridation program to provide decision-makers with economic information for assessing its usefulness. METHODS: An approach adapted from economic evaluation was used to: (1) build a logic model for Quebec's water fluoridation program; (2) determine its implementation cost; and (3) analyze its cost-effectiveness. Documentary analysis was used to build the logic model. Program cost was calculated using data from 13 municipalities that adopted fluoridation between 2002 and 2010 and two that received only infrastructure grants. Other sources were used to collect demographic data and calculate costs for caries treatment including costs associated with travel and lost productivity. RESULTS: The analyses showed the water fluoridation program was cost-effective even with a conservatively estimated 1 % reduction in dental caries. The benefit-cost ratio indicated that, at an expected average effectiveness of 30 % caries reduction, one dollar invested in the program saved $71.05-$82.83 per Quebec's inhabitant in dental costs (in 2010) or more than $560 million for the State and taxpayers. CONCLUSION: The results showed that the drinking-water fluoridation program produced substantial savings. Public health decision-makers could develop economic arguments to support wide deployment of this population-based intervention whose efficacy and safety have been demonstrated and acknowledged.

Screening for glaucoma using GDx-VCC in a population with ≥1 risk factors.

OBJECTIVE: To estimate the diagnostic accuracy of the GDx-VCC for glaucoma screening in a population with ≥1 risk factors for glaucoma. DESIGN: Cross-sectional evaluation of a diagnostic test for screening. PARTICIPANTS: Two hundred forty-seven community-based volunteer participants with risk factors for glaucoma. METHODS: The peripapillary retinal nerve fibre layers (RNFL) of participants' eyes were scanned using the GDx-VCC. Based on an ophthalmologic examination and frequency doubling perimetry, eyes were classified into 4 categories: normal, possible glaucoma, probable glaucoma, and definitive glaucoma. The sensitivities, specificities, positive and negative predictive values, and positive and negative likelihood ratios of the RNFL parameters were calculated. RESULTS: The right eyes were retained for analyses. After excluding 5 eyes because of missing data and 23 eyes because of poor scan quality, the data of 219 right eyes were analyzed. Four eyes had definitive glaucoma. The best performing parameter was the nerve fibre indicator using a cutoff of 35 with a sensitivity of 75% (95% CI 19.4-99.4) at a specificity of 95% (95% CI 91.3-97.3), a positive predictive value of 25 (95% CI 4.3-48.1), a negative predictive value of 99 (95% CI 97.5-100.0), a positive likelihood ratio of 16 (95% CI 6.69-32.5), and a negative likelihood ratio of 0.20 (95% CI 0.05-1.44). CONCLUSIONS: The GDx-VCC has inadequate sensitivity for screening of definitive glaucoma.

Partnership for fragility bone fracture care provision and prevention program (P4Bones): study protocol for a secondary fracture prevention pragmatic controlled trial.

BACKGROUND: Fractures associated with bone fragility in older adults signal the potential for secondary fracture. Fragility fractures often precipitate further decline in health and loss of mobility, with high associated costs for patients, families, society and the healthcare system. Promptly initiating a coordinated, comprehensive pharmacological bone health and falls prevention program post-fracture may improve osteoporosis treatment compliance; and reduce rates of falls and secondary fractures, and associated morbidity, mortality and costs. METHODS/DESIGN: This pragmatic, controlled trial at 11 hospital sites in eight regions in Quebec, Canada, will recruit community-dwelling patients over age 50 who have sustained a fragility fracture to an intervention coordinated program or to standard care, according to the site. Site study coordinators will identify and recruit 1,596 participants for each study arm. Coordinators at intervention sites will facilitate continuity of care for bone health, and arrange fall prevention programs including physical exercise. The intervention teams include medical bone specialists, primary care physicians, pharmacists, nurses, rehabilitation clinicians, and community program organizers.The primary outcome of this study is the incidence of secondary fragility fractures within an 18-month follow-up period. Secondary outcomes include initiation and compliance with bone health medication; time to first fall and number of clinically significant falls; fall-related hospitalization and mortality; physical activity; quality of life; fragility fracture-related costs; admission to a long term care facility; participants' perceptions of care integration, expectations and satisfaction with the program; and participants' compliance with the fall prevention program. Finally, professionals at intervention sites will participate in focus groups to identify barriers and facilitating factors for the integrated fragility fracture prevention program.This integrated program will facilitate knowledge translation and dissemination via the following: involvement of various collaborators during the development and set-up of the integrated program; distribution of pamphlets about osteoporosis and fall prevention strategies to primary care physicians in the intervention group and patients in the control group; participation in evaluation activities; and eventual dissemination of study results.

Estimation of ocular rigidity in glaucoma using ocular pulse amplitude and pulsatile choroidal blood flow.

PURPOSE: Theoretical models and animal studies have suggested that scleral rigidity plays an important role in the pathogenesis of glaucoma. The aim of this study was to present a noninvasive technique for estimating ocular rigidity (E) in vivo, and to compare the estimated rigidity between patients with open-angle glaucoma (OAG); ocular hypertension (OHT); suspect glaucomatous disc (GS); and normal subjects (N). We hypothesized that OHT patients would have higher rigidity. METHODS: All patients underwent measurements of ocular pulse amplitude (OPA) using dynamic contour tonometry, pulsatile choroidal blood flow (ChBFP) using laser Doppler flowmetry; axial length (AL); and assessment of automated visual field mean deviation (MD). The ratio between OPA and ChBFP was calculated according to the Friedenwald's equation of ocular rigidity. The calculated ratio is denoted as (ER). The average ER values of the four diagnostic groups were compared using nonparametric tests. The relationship between ER and other ocular and systemic factors was examined using correlation and regression analysis. RESULTS: A total of 257 subjects were included in the study (56 N, 108 OAG, 48 GS, and 45 OHT). ER correlated negatively with AL and positively with MD, signifying that a lower rigidity was associated with a longer eye and a worse (more negative) MD. ER was also found to be highest in OHT (0.235 ± 0.16) and lowest in OAG (0.188 ± 0.14; P = 0.01). CONCLUSIONS: Estimated coefficient of ocular rigidity by OPA and ChBFP suggested that glaucoma patients had the lowest rigidity and OHT the highest. It supports the idea that a more compliant ocular shell may predispose the optic nerve head to intraocular pressure (IOP)-related damage.

Utilisation des neurostimulateurs médullaires dans le traitement de la douleur chronique non cancéreuse / Use of medullary neurostimulators in the treatment of chronic non-cancer pain

INTRODUCTION: La douleur chronique est définie par l'Association internationale pour l'étude de la douleur (IASP) comme étant une douleur persistant au-delà du délai normal de trois mois de guérison des tissus. Selon une étude récente, elle touche 18,9 % de la population âgée de 18 ans et plus au Canada et 15,7 % au Québec. La douleur chronique peut être d'origine cancéreuse ou non. Parmi les douleurs chroniques non cancéreuses (DCNC), les douleurs neuropathiques sont connues comme étant les plus réfractaires au traitement médical conventionnel (TMC). Elles affectent approximativement de 1,5 % à 8 % de la population générale. Au-delà de la douleur ressentie, les patients souffrant de douleur chronique éprouvent souvent une diminution de leur qualité de vie et de leur capacité fonctionnelle. Le traitement de la douleur chronique comprend la correction de la cause sous-jacente et le traitement pharmacologique (analgésiques, anticonvulsivants et opiacés), physique (ergothérapie et physiothérapie) ou autres (suivi psychologique, massothérapie et acupuncture). Lorsque la douleur est réfractaire à ces traitements, le recours à la neuromodulation peut être envisagé. Les dispositifs de neuromodulation sont coûteux et exigent l'expertise de plusieurs professionnels pour leur implantation et pour le suivi des personnes implantées; de plus, les besoins ne sont pas tous satisfaits et même s'accroissent. Quelqu

INTRODUCTION: Chronic pain is defined by the International Association for the Study of Pain (IASP) as pain persisting beyond normal tissue healing time, assumed to be three months. According to a recent study, it affects 18.9% of the population aged 18 years or older in Canada and 15.7% in Québec. Chronic pain may or may not originate from cancer. Chronic non-cancer pain (CNCP) includes neuropathic pain, known to be the most refractory to conventional medical management (CMM). It affects approximately from 1.5% to 8% of the general population. Apart from the pain they feel, patients with chronic pain often experience reduced quality of life and functional capacity. The management of chronic pain involves correcting the underlying cause and providing pharmacological treatment (analgesics, anticonvulsants and opioids), physical treatment (occupational therapy and physiotherapy) or other treatments (psychotherapy, massotherapy and acupuncture). When pain is refractory to these treatments, the use of neuromodulation may be considered. Neuromodulation devices are costly and require the expertise of several professionals to implant them and to follow up implanted patients. Moreover, the need for these

Savings from the use of a probiotic formula in the prophylaxis of antibiotic-associated diarrhea.

OBJECTIVE: Antibiotic-associated diarrhea (AAD) and particularly Clostridium difficile-associated diarrhea (CDAD) are the most common causes of healthcare associated infectious diarrhea. A double-blind, dose response, placebo-controlled trial of the probiotic formula (Bio-K+ Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R formula) for prophylaxis of AAD and CDAD was published in 2010. The Bio-K+ Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R formula is a registered trademark of Bio-K Plus International Inc. (Laval, Québec, Canada). Results indicated that the incidence of AAD and CDAD were lower for patients assigned to the probiotic formula compared with the placebo option. The present study aims to estimate the savings in direct medical costs that might result from the use of two different doses of the probiotic formula vs placebo. METHODS: A cost-consequence analysis was conducted to compare the two doses of the probiotic formula compared to placebo. The analysis was based upon published data and adjusted to the North American context. RESULTS: Economic analyses showed that the use of the probiotic formula would result in estimated mean per patients savings of US$1968 for the single dose and US$2661 for the double dose compared with the placebo option if used an average of 13 days by all patients at risk of developing AAD and CDAD. LIMITATIONS: Several key parameters considered within the economic model were not captured within the Gao et al. study. Numerous sensitivity analyses were conducted to address this issue. CONCLUSION: The use of the probiotic formula in prophylaxis of AAD and CDAD would lead to estimated savings in direct medical costs that would substantially offset its acquisition cost. Treating 1000 hospitalized patients on antibiotics with the double dose of the product compared to current practice would save a single payer system the sum of $2,661,218.

Screening for glaucoma with Moorfields regression analysis and glaucoma probability score in confocal scanning laser ophthalmoscopy.

OBJECTIVE: To compare the validity of Moorfields regression analysis (MRA) and glaucoma probability score (GPS) of the confocal scanning laser ophthalmoscopy (Heidelberg retina tomograph 3; HRT3) in detecting glaucomatous optic nerve damage in a screening population. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Subjects at high risk for development of open-angle glaucoma (OAG). METHODS: All subjects underwent confocal scanning ophthalmoscopy (Heidelberg retina tomograph; HRTII) testing, visual fields testing with frequency-doubling technology perimetry (FDT), and a standard ophthalmologic examination. All HRTII images were reprocessed with HRT3. Based on an ophthalmologic examination and FDT results, eyes were classified into 4 categories: normal, possible glaucoma, probable glaucoma, and definitive glaucoma. Main outcome measures included sensitivity and specificity of HRTII/MRA, HRT3/MRA, HRT3/GPS, and combination HRT3/MRA/GPS. RESULTS: The left eyes of 221 of 291 subjects were included; 4 (1.8%) eyes were classified as definitively having glaucoma. Depending on the reference standard diagnosis as well as on the borderline test-positive definition of the HRTII-3, sensitivity and specificity varied between 36.4% and 100%. For HRTII/MRA, 88.2% to 96.5%, 54.5% to 100%, and 74.5% to 93.6%; for HRT3/MRA, 61.9% to 100% and 64.3% to 85.2%; for HRT3/GPS, 85.7% to 100%; and for combination HRT3/MRA/GPS, 73.4% to 78.2%. CONCLUSIONS: In this pilot study, the MRA of the HRT3 appears to be more sensitive but less specific than the MRA in the HRTII version. The GPS, although somewhat less specific than MRA (and some discs are nonclassifiable by this technique), had greater sensitivity and as a screening method may have the additional advantage of being contour-line independent.

Combining rim area to disc area asymmetry ratio and Moorfields regression analysis of confocal scanning laser ophthalmoscopy for glaucoma screening.

OBJECTIVE: To determine the utility of combining rim area to disc area asymmetry ratio (RADAAR) and Moorfields regression analysis (MRA) to detect primary open-angle glaucoma (POAG) using confocal scanning laser ophthalmoscopy (CSLO) (Heidelberg retina tomograph 3 (HRT3)) in high-risk populations. DESIGN: Cross-sectional study. PARTICIPANTS: Subjects with high risk for developing POAG. METHODS: Subjects underwent HRT, frequency doubling technology perimetry (FDT), and complete ophthalmic examination. Based on an ophthalmologic examination and FDT results of the worse eye, subjects were classified into 4 categories: normal, possible glaucoma, probable glaucoma, and definite glaucoma. Main outcome measures included sensitivities (Se), specificities (Sp), positive and negative predictive values (PPV, NPV), and positive and negative likelihood ratios (PLR, NLR) of the MRA, RADAAR, and combined MRA- RADAAR tests. RESULTS: Of 375 subjects, 11 were classified as having definite glaucoma. Depending on the reference standard, range results for Se, Sp, PPV, NPV, PLR, and NLR were, respectively, 57.7% to 100%; 55.1% to 85.4%; 6.3% to 39%; 92.6% to 100%; 1.97 to 4.9; 0 to 0.49 for MRA; 11.5% to 27.3%; 98.1% to 98.8%; 30% to 60%; 87.4% to 97.8%; 9.29 to 14.1; and 0.74 to 0.89 for RADAAR; and 57.7% to 90.9%; 81.3% to 85.1%; 12.8% to 38.5%; 92.6% to 99.7%; 3.87 to 4.85; 0.11 to 0.50 for combination MRA-RADAAR. DISCUSSION: When using HRT in populations at high risk for glaucoma, RADAAR had a higher specificity than MRA in identifying glaucoma. When patients were classified as borderline on MRA, combining RADAAR values decreased the number of false-positives as well, and may be recommended when high specificity is required.

The validity of screening for open-angle glaucoma in high-risk populations with single-test screening mode frequency doubling technology perimetry (FDT).

PURPOSE: To evaluate whether a single frequency doubling perimetry (FDT) test is a valid screening tool to detect open-angle glaucoma (OAG) in high-risk populations. PATIENTS AND METHODS: All participants underwent frequency doubling Technology perimetry (FDT C-20-5 algorithm, Carl Zeiss Meditec Inc, Dublin, CA) and complete ophthalmic examination. FDT printouts were classified according to Iwasaki and Patel protocols. Gold-standard was clinical diagnosis of glaucomatous optic nerve damage. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value, negative predictive value, positive, and negative likelihood ratios of a single-test screening FDT. RESULTS: Data of 445 right eyes and 408 left eyes of participants were analyzed. On the basis of clinical diagnosis, 19 right eyes (4.3%) and 20 left eyes (4.9%) had glaucoma. Depending on the gold standard used, the range of sensitivity was between 40.7% and 78.9%, 66% and 70% for specificity, 7.7% and 25.2% for positive predictive value, 82.3% and 98.6% for negative predictive value, 1.25 and 2.37 for positive likelihood ratio, and 0.32 and 0.87 for negative likelihood ratio. The κ coefficient of agreement between the FDT classifications as described by Iwasaki et al and Patel et al was 0.936 in right eyes and 0.935 in left eyes. CONCLUSIONS: The sensitivity and specificity of a single reliable screening FDT test were low. Thus, a single screening FDT test in even a high-risk population has poor validity and steps should be taken to better define the target population before testing, and enhance the FDT screening strategy.

Assessment of factors affecting the difference in intraocular pressure measurements between dynamic contour tonometry and goldmann applanation tonometry.

PURPOSE: To determine if the difference in intraocular pressure (IOP) measurements between dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) is correlated with axial length (AL), and to assess the possible influence of age, sex, central corneal thickness (CCT), corneal hysteresis (CH), ocular pulse amplitude (OPA), and glaucoma status on the difference in IOP measurements between the 2 instruments (ΔIOP=DCTIOP- GATIOP). METHODS: Two hundred sixty-oneparticipants (509 eyes) in these 4 groups were included: 53 normal individuals (N; 106 eyes), 112 glaucoma patients (OAG; 212 eyes), 52 glaucoma suspects (GS; 103 eyes), and 44 patients with ocular hypertension (OHT; 88 eyes). The patients who had had an incisional ocular surgery were excluded. All participants underwent IOP evaluation with DCT and GAT and AL, CCT, and CH measurements. The influence of age, sex, AL, CCT, CH, OPA, and glaucoma diagnostic status on ΔIOP was evaluated using correlation analysis and analysis of variance (ANOVA). Right (OD) and left eyes (OS) were analyzed separately. RESULTS: ΔIOP was higher in eyes with longer axial lengths (OD: r=0.142, P=0.02; OS: r=0.233, P<0.001). ΔIOP also correlated with CH (OD: r=-0. 127, P=0.04; OS: r=-0.169, P=0.01), in which the ΔIOP increased as CH decreased (corresponding to less rigid corneas). OPA also correlated negatively with ΔIOP, but the correlation was only statistically significant in left eye (OD: r=-0.112, P=0.08; OS: r=-0.124, P=0.05). Age, CCT, sex, and diagnostic status did not influence ΔIOP significantly. CONCLUSIONS: GAT underestimated IOP more compared with DCT in patients with longer axial length and in patients with lower corneal hysteresis.

Screening for glaucoma in high-risk populations using optical coherence tomography.

OBJECTIVE: To estimate the diagnostic accuracy of Stratus optical coherence tomography (OCT) for glaucoma screening in high-risk populations. DESIGN: Cross-sectional evaluation of a diagnostic test for screening. PARTICIPANTS: Three hundred thirty-three community-based volunteer participants with risk factors for glaucoma. METHODS: The optic nerve and peripapillary retinal nerve fiber layer (RNFL) of participants' eyes were scanned using the Stratus OCT. Based on an ophthalmologic examination and frequency doubling perimetry, eyes were classified into 4 categories: normal, possible glaucoma, probable glaucoma, and definitive glaucoma. MAIN OUTCOME MEASURES: The sensitivities, specificities, positive and negative likelihood ratios of the RNFL, optic disc parameters, and their combinations were calculated. RESULTS: The right eyes were retained for analyses. After excluding eyes with missing data or with poor quality scans, the data of 210 right eyes were analyzed. Six eyes had definitive glaucoma. Combining the best performing optic nerve head parameters (cup diameter or cup/disc vertical ratio or cup/disc area ratio) and RNFL parameters (superior average or inferior average or overall average) using AND-logic resulted in a sensitivity of 67% (95% confidence interval [CI], 24%-94%), specificity of 96% (95% CI, 92%-98%), a positive likelihood ratio of 17.08 (95% CI, 7.06-41.4), and a negative likelihood ratio of 0.35 (95% CI, 0.11-1.08). CONCLUSIONS: When adequate quality scans may be obtained, the Stratus has moderate sensitivity and high specificity for definitive glaucoma. Specificity is increased when parameters from both the optic nerve head and RNFL scans are combined.

Racial variability of glaucoma risk factors between African Caribbeans and Caucasians in a Canadian urban screening population.

BACKGROUND: The significance of race in the development and progression of glaucoma remains controversial, although in most cases the evidence shows greater prevalence and progression of the disease in African American populations. The purpose of this study was to determine the impact of the African Caribbean race on the variability of risk factors for glaucoma in an urban Canadian screening population. STUDY DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Participants with high risk for development of open-angle glaucoma. METHODS: Participants underwent confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph),frequency-doubling technology (FDT) perimetry, and complete ophthalmic examination during a high-risk glaucoma screening clinic. Statistical analysis was performed comparing the data gathered from these tests in the different racial groups. Student's t tests as well as Pearson's c2 tests were done. RESULTS: Racial breakdown included 64 African Caribbeans (22%) and 224 Caucasians (78%). Racial groups had similar female/male ratios, but Caucasians were significantly older (66 [SD 12] years) than African Caribbeans (56 [SD12] years) ( p = 0.001). African Caribbeans had significantly higher intraocular pressure (IOP) ( p < 0.001); thinner central corneal thickness (CCT) ( p < 0.001); greater cup/disc ratio ( p = 0.016), disc area ( p < 0.001), cup area ( p = 0.002), and cup/disc area ratio ( p = 0.009); and smaller rim/disc area ratio ( p = 0.009). The latter optic disc parameter differences were not statistically different when corrected for disc area differences. CONCLUSIONS: In this study, African Caribbeans in a Canadian urban setting were associated with increased risk factors for open-angle glaucoma development, including higher IOP and thinner CCT. The larger cup/disc and cup/disc area ratios of the African Caribbean group were directly correlated to disc area differences between the 2 groups.

Validity of screening for glaucomatous optic nerve damage using confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph II) in high-risk populations: a pilot study.

PURPOSE: To evaluate whether confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph II [HRT II], Heidelberg Engineering, Heidelberg, Germany) is a valid tool for the detection of glaucomatous optic nerve damage. DESIGN: Observational, cross-sectional, nonconsecutive study in Montreal, Canada. PARTICIPANTS: Three hundred three nonconsecutive, high-risk persons were enrolled during a 6-month period. METHODS: Participants underwent HRT II testing and a standard ophthalmologic examination, including gonioscopy, intraocular pressure measurement, and optic disc grading. MAIN OUTCOME MEASURES: Positive likelihood ratio (PLR) and negative likelihood ratio (NLR), sensitivities and specificities, positive predictive value (PPV) and negative predictive value (NPV), and kappa coefficients of agreement of Moorfields regression analysis (MRA), cup shape measure (CSM), height variation contour (HVC), and mean retinal nerve fiber layer thickness (MRNFL). RESULTS: Three hundred three participants were enrolled, and 291 were examined clinically; 21 (7.2%) were found to have glaucoma. Heidelberg Retina Tomograph II testing was performed successfully and was of acceptable quality in 531 of 601 eyes (88%). When MRA was compared with the clinically based diagnosis, the weighted kappa coefficient was kappa = 0.567 (95% confidence interval [CI], 0.42-0.71) for the right eye and kappa = 0.516 (95% CI, 0.37-0.66) for the left eye. Best kappa coefficient of agreement was seen when normals were grouped with suspects in both clinical and MRA diagnosis (kappa = 0.604; 95% CI, 0.409-0.799 in the right eye). Depending on the gold standard and test-positive definitions for glaucoma, specificity ranged from 87% to 97%, sensitivity from 25% to 100%, PPV from 28% to 68%, NPV from 84% to 100%, PLR from 5.0 to 19.2, and NLR from 1.3 to 6.2. When CSM, HVC, and MRNFLT were compared with clinical diagnosis, all outcome measures were found to have lower ranges: specificity from 46.9% to 83.7%, sensitivity from 36.5% to 76.9%, PPV from 6% to 36%, NPV from 80% to 99%, PLR from 0.8 to 4.0, NLR from 0.9 to 3.0. CONCLUSIONS: The results of this study suggest that a glaucoma screening program may be effective in detecting glaucoma when targeting high-risk populations. Heidelberg Retina Tomograph II testing may prove to be a useful tool in detecting glaucomatous optic nerve damage and could be used as part of a complete glaucoma screening protocol.

The effect of compression on clinical diagnosis of glaucoma based on non-analyzed confocal scanning laser ophthalmoscopy images.

BACKGROUND AND OBJECTIVE: To evaluate the effect of different image compression formats of non-analyzed Heidelberg Retina Tomography (HRT; Heidelberg Engineering, Heidelberg, Germany) images on the diagnosis of glaucoma by ophthalmologists. MATERIALS AND METHODS: Thirty-three topographic and reflectance images taken with the HRT representing different levels of disease were transformed using nine different compression formats. Three independent ophthalmologists, masked as to contour line and stereometric parameters, classified the original and compressed HRT images as normal, suspected glaucoma, or glaucoma, and Kappa agreement coefficients were calculated. RESULTS: The Tagged Image File Format had the largest file size and the Joint Photographic Experts Group (JPEG) 2000 format had the smallest size. The highest Kappa coefficient value was 1.00 for all ophthalmologists using the Tagged Image File Format. Kappa values for JPEG formats were all in the range of good to excellent agreement. Kappa values were lower for Portable Network Graphic and Graphics Interchange Format compression formats. CONCLUSION: Image compression with JPEG 2000 at a ratio of 20:1 provided sufficient quality for glaucoma analysis in conjunction with a relatively small image size format, and may prove to be attractive for HRT telemedicine applications. Further clinical studies validating the usefulness of interpreting non-analyzed HRT images are required.

Screening for primary open-angle glaucoma in the developed world: are we there yet?

BACKGROUND: In 1995, the Quebec Agency for Health Services and Technology Assessment (AETMIS) stated that a formal screening program for primary open-angle glaucoma (POAG) could not be recommended for the province of Quebec, owing to "a high degree of uncertainty and because of the high cost such a program would entail." The purpose of this article was to evaluate the possibility of instituting a POAG screening program in light of recent advances in the diagnosis and treatment of glaucoma. METHODS: We reviewed new developments that have occurred since the mid to late 1990s in the field of glaucoma. Changes that could positively influence the feasibility and organization of future glaucoma screening programs were identified. RESULTS: New technologies, including confocal scanning laser ophthalmoscopy (HRT II), optical coherence tomography (Stratus OCT), and scanning laser polarimetry with variable corneal compensation (GDx-VCC), permit early detection of optic nerve and nerve fibre layer structural damage. Together with advanced psychophysical tests (frequency doubling perimetry and short wavelength automated perimetry) for earlier detection of functional damage, they provide an increased understanding of the diagnosis and monitoring of POAG. Elevated intraocular pressure (IOP) remains the most important risk factor for glaucoma. Clinical trials indicate that lowering IOP at different stages of the disease can arrest or decrease its rate of progression. Moreover, it is important to assess pachymetry because IOP measurements are influenced by central corneal thickness. Finally, new treatments, such as prostaglandin analogues or selective laser trabeculoplasty, are safer and may also achieve lower intraocular pressures. INTERPRETATION: Health policy involves the investment of public resources, and cost-effectiveness analyses for POAG screening are heavily weighted by the degree of uncertainty that glaucoma screening can be effectively and reliably achieved. The many new developments and advancements outlined herein, combined with the possible increasing prevalence of POAG, necessitate the re-evaluation of screening for primary open-angle glaucoma.