Epidemiology Study of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION)

Study Overview
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Brief Summary
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The objectives of this study were to: (1) evaluate the natural history of non-arteritic anterior ischemic optic neuropathy (NAION); (2) estimate the population incidence of NAION; and (3) identify potential risk factors for NAION.

Detailed Description
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The study population consisted of members of the Ingenix Normative Health Informatics (NHI) Database during 01/01/2003 through 12/31/2007, who were 18 years of age or older with at least 183 days of continuous enrollment in the database and without any doctor visits associated with a diagnosis of ischemic optic neuropathy during the 183 days prior to cohort entry. From the study population, patients with a claim associated with an ischemic optic neuropathy diagnosis code were identified as potential NAION cases (n = 3,732). From the potential NAION cases, definite and possible NAION cases were identified using medical record review and a claims algorithm (n=1,283). From the study population, patients without a claim associated with an ischemic optic neuropathy diagnosis code were randomly selected as controls (n = 20,000)

Official Title
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The Detection and Epidemiology of NAION in a Commercially Insured Population in the United States.

Conditions
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Anterior Ischemic Optic Neuropathy, Ischemic Optic Neuropathy

Intervention / Treatment
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* Other: No intervention given in this observational study
* Other: No intervention given in this observational study


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Member of the Ingenix Normative Health Informatics (NHI) Database during 01/01/2003 through 12/31/2007 18 years of age or older Had at least 183 days of continuous enrollment in the database No doctor visits associated with a diagnosis of ischemic optic neuropathy during the 183 days prior to cohort entry Exclusion Criteria: Less than 18 years of age Less than 183 days of continuous enrollment in the database At least one doctor visit associated with a diagnosis of ischemic optic neuropathy during the 183 days prior to cohort entry

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| NAION cases<br>From the study population, patients with a claim associated with an ischemic optic neuropathy diagnosis code were identified as potential NAION cases (n = 3,732). From the potential NAION cases, definite and possible NAION cases were identified using medical record review and a claims algorithm (n=1,283). Data from definite and possible NAION cases contributed to the analysis. | Other: No intervention given in this observational study<br>* No intervention given in this observational study<br>|
| Controls<br>From the study population, patients without a claim associated with an ischemic optic neuropathy diagnosis code were randomly selected as controls (n = 20,000) | Other: No intervention given in this observational study<br>* No intervention given in this observational study<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Age | Person-years estimated by dividing the number of Controls participants by the derived sampling fraction (20,000 divided by the total person-time at risk). Age categorized by years. | 01-January-2003 up to 31-December-2007 | 
| Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Sex | Person-years estimated by dividing the number of Controls participants by the derived sampling fraction (20,000 divided by the total person-time at risk). Sex categorized as Female or Male. | 01-January-2003 up to 31-December-2007 | 
| Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Calendar Year | Person-years estimated by dividing the number of Controls participants by the derived sampling fraction (20,000 divided by the total person-time at risk). Calendar years include years 2003 to 2007. | 01-January-2003 up to 31-December-2007 | 
| Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Region | Person-years estimated by dividing the number of Controls participants by the derived sampling fraction (20,000 divided by the total person-time at risk). Region of the United States categorized as Northeast, Midwest, South, and West. | 01-January-2003 up to 31-December-2007 | 
| Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Baseline Risk Factors | Person-years estimated by dividing number of Controls (20,000) by derived sampling fraction (total person-time at risk). Risk factors include diabetes, smoking, obesity, erectile dysfunction, hyperlipidemia, myocardial infarction, other coronary artery disease, congestive heart failure, hypertension, use of beta or calcium channel blockers, angiotensin-converting enzyme inhibitors, nitrates, anti-platelet agents, diuretics, and recent phosphodiesterase type 5 (PDE-5) inhibitors use. Recent use=any dispensing in the 60 days preceding date of diagnosis for NAION cases or index date for Controls. | 01-January-2003 up to 31-December-2007 | 
| Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Comorbid Diagnoses | Person-years estimated by dividing the number of Controls participants by the derived sampling fraction (20,000 divided by the total person-time at risk). Comorbid diagnoses categorized according to the International Classification of Diseases ninth-edition (ICD-9) diagnoses. Categories include Occlusion and stenosis of precerebral arteries (Occlusion / Stenosis), Other disorders of bone and cartilage (Bone and Cartilage), Symptoms involving head and neck (Head and Neck), and Other ill defined and unknown causes of morbidity and mortality (Ill defined / Unknown causes). | 01-January-2003 up to 31-December-2007 | 
| Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by PDE-5 Inhibitor Use | Person-years estimated by dividing the number of Controls by the derived sampling fraction (20,000 divided by total person-time at risk). PDE-5 inhibitor use categorized by frequency of use in the number of days specific preceding diagnosis for NAION Cases or preceding the index date for Controls: Recent use=any dispensing in the preceding 60 days; Any use=any PDE-5 inhibitors use; Chronic use=at least a total of 26 days supply or 5 dispensings in the preceding 183 days; Non-chronic use=any dispensing in the preceding 183 days that does not meet the criteria for chronic use; Never use=none. | 01-January-2003 up to 31-December-2007 | 
| Number of Participants With NAION by Time Course of Visual Change Onset: Intermittent, Abrupt (Acute), or Chronic (Adjudicated by Medical Record Review) |  | 01-January-2003 up to 31-December-2007 | 
| Incidence Rate Ratio Between NAION Risk Factors and Resolution of Visual Symptoms of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) | Categorized by risk factors of age (years) and sex (male or female). Incidence rate ratio and the 95% confidence interval adjusted for all the other covariates in the table. | 01-January-2003 up to 31-December-2007 | 
| Incidence Rate Ratio Between NAION Risk Factors and Recurrence of Visual Symptoms of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) | Categorized by risk factors of age (years) and sex (male or female). Incidence rate ratio and the 95% confidence interval adjusted for all the other covariates in the table. | 01-January-2003 up to 31-December-2007 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Phosphodiesterase type 5 inhibitors, non-arteritic anterior ischemic optic neuropathy, descriptive epidemiology study