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

• Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Age [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  
• Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Sex [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  
• Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Calendar Year [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  
• Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Region [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  
• Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Baseline Risk Factors [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  
• Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by Comorbid Diagnoses [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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).
  
  
• Crude Incidence Rate of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) Per 1000 Person-years by PDE-5 Inhibitor Use [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  
• Number of Participants With NAION by Time Course of Visual Change Onset: Intermittent, Abrupt (Acute), or Chronic (Adjudicated by Medical Record Review) [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  
• Incidence Rate Ratio Between NAION Risk Factors and Resolution of Visual Symptoms of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  
• Incidence Rate Ratio Between NAION Risk Factors and Recurrence of Visual Symptoms of Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) [ Time Frame: 01-January-2003 up to 31-December-2007 ] [ Designated as safety issue: Yes ]
  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.
  
  

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)