Table 2.
Assessment and classification of the evaluated medical conditions
| Medical Condition | Description of Assessment | Definition of Categories |
|---|---|---|
| Determined from Questionnaire | ||
| Depression | Patient Health Questionnaire (PHQ-9) | Moderate or greater depression defined as PHQ-9 ≥ 10 |
| Determined from Examination | ||
| Age-Related Macular Degeneration | Canon Non-Mydratic Retinal Camera CR6-45NM | Early AMD: presence of drusen and/or pigmentary abnormalities; late AMD: presence of choroidal neovascularization and/or geographic atrophy; few participants had late AMD, so participants were classified as early/late AMD |
| Visual Impairment | ARK-760 autorefractor | Participants with presenting visual acuity of 20/40 or better in either eye were classified as having normal sight. Participants with presenting visual acuity worse than 20/40, but postrefraction visual acuity in either eye were 20/40 or better, were classified as having uncorrected refractive error. Participants with visual acuity worse than 20/40 after autorefraction, or who self-reported not being able to see light with both eyes open, were classified as having visual impairment. |
| Cardiorespiratory Fitness | Treadmill-based submaximal test. | Low fitness: < 20th percentile; moderate fitness: 20–59th percentile; high fitness ≥ 60th percentile for age and gender. |
| Chronic Obstructive Pulmonary Disease | Objective pulmonary function testing using Ohio 822/827 dry-rolling seal volume spirometers | GOLD classifications when FEV1/FVC < 0.70: Mild COPD: FEV1 ≥ 80% predicted; Moderate: 50% ≤ FEV1 < 80% predicted; Severe: 30% ≤ FEV1 < 50% predicted; Very severe: FEV1 < 30% predicted; few participants had very severe COPD, so classifications were mild, moderate, and severe COPD. |
| Hearing Impairment | Calculating the average of air conduction pure-tone thresholds; low pure-tone average (LPTA) and high pure-tone average (HPTA). | Hearing within normal limits (LPTA & HPTA ≤ 25 dB), mild hearing loss (LPTA or HPTA 26–40 dB) and moderate or greater hearing loss (LPTA or HPTA > 40 dB) |
| Non-Proliferative Retinopathy | Canon Non-Mydratic Retinal Camera CR6-45NM | No retinopathy, mild non-proliferative retinopathy, moderate-to-severe non-proliferative retinopathy; based on presence of 1 or more retinal microaneurysms or retinal blot hemorrhages using the Early Treatment Diabetic Retinopathy Study grading criteria. |
| Weight Status | Measured body mass index | Obesity defined as ≥ 30 kg/m2 Underweight defined as < 18.5 kg/m2 |
| Peripheral Arterial Disease | Ankle Brachial Index (ABI) from measured upper and lower extremity blood pressure assessment. | Normal ABI (1–1.4) and abnormal ABI (< 1 or > 1.4) |
| Peripheral Neuropathy | 5.07 Semmes-Weinstein nylon monofilament | Peripheral neuropathy defined as at least 1 insensate area in either foot. |
| Physical Inactivity | Accelerometry over a 7-day period, and only including those providing at least 4 days of 10+ hrs/day of monitoring. | Physical inactivity defined as engaging in < 150 min/wk of accelerometer-determined moderate-to-vigorous physical activity (1-min bouts). |
| Determined from Laboratory Assessment | ||
| Chronic Kidney Disease | Glomerular filtration rate was assessed from the CKD Epidemiology equation based on specified race, sex, and creatinine level. | < 60 mL/min per 1.73 m2 |
| Elevated C-Reactive Protein (CRP) | Latex-enhanced nephelometry. | > 0.3 mg/dL |
| Elevated Fasting Glucose | Hexokinase method | ≥ 126 mg/dL |
| Elevated LDL Cholesterol | Friedewald formula | ≥ 160 mg/dL |
| Elevated Total Cholesterol | Measured enzymatically in serum using the Roche Hitachi method. | > 240 mg/dL |
| Elevated Triglycerides | Measured enzymatically in serum. | ≥ 200 mg/dL |
| Low HDL Cholesterol | Measured enzymatically in serum. | < 40 mg/dL |
| Hypertension | Measured systolic and diastolic blood pressure; average of 3–4 measurements. | ≥ 140 mmHg systolic or ≥ 90 mmHg diastolic |
| Smoking (cotinine) | Serum cotinine, a biological measure of smoking status, was measured by an isotope dilution-high performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry. | Serum cotinine levels of > 1.78 ng/mL for men and > 4.47 ng/mL for women were assessed to differentiate smokers from non-smokers |