Table 1.
Definition on measurement of variables and covariables: Search criteria from the NHANES 2009-2010 and 2011-2012 survey results
| Patient characteristic | NHANES variable code | Notes |
|---|---|---|
| TSH (mIU/L) | LBDTSH1S | Overt HT: TSH >4.0 mIU/L + FT4 < 0.8 ng/dL or RX utilization to treat HT Subclinical HT: TSH >4.0 mIU/L + FT4 ≥ 0.8 ng/dL Without RX to treat HT Disease free: TSH 0.4-4.0 mIU/L |
| FT4 (ug/dL) | LBXT4F | |
| Age (years) | RIDAGYR | |
| Sex | RIAGENDR | Male = 1; female = 2 |
| Race | RIDETH1 | Non-Hispanic White = 3; Non-Hispanic Black = 4; Mexican American or other Hispanic = 1 or 2; other = 5 |
| Insurance statusa | ||
| Private | HIQ031A | =14 |
| Medicare | HIQ031B | =15 |
| Medi-Gap | HIQ031C | =16 |
| Medicaid | HIQ031D | =17 |
| SCHIP | HIQ031E | =18 |
| Military | HIQ031F | =19 |
| Indian Health Service | HIQ031G | =20 |
| State-sponsored | HIQ031H | =21 |
| Other government | HIQ031I | =22 |
| Other | HIQ031J | =23 |
| No coverage | HIQ031AA | =40 |
| Comorbidities, n (%) | ||
| Angina | MCQ160D | =1 (yes) |
| Arthritis | MCQ160A | =1 (yes) |
| Asthma | MCQ010 | =1 (yes) |
| Cancer | MCQ220 | =1 (yes) |
| Cerebrovascular accidents | MCQ160F | =1 (yes) |
| COPDb | MCQ160G, MCQ160K | =1 (yes) |
| Chronic renal failure | KIQ022 | =1 (yes) |
| Congestive heart failure | MCQ160B | =1 (yes) |
| Coronary heart disease | MCQ160C | =1 (yes) |
| Diabetes | DIQ010 | =1 (yes) |
| Hepatic conditions | MCQ160I | =1 (yes) |
| Hypertension | BPQ020 | =1 (yes) |
| Hyperlipidemia | BPQ080 | =1 (yes) |
| Ischemic heart diseasec | MCQ160D, MCQ160E | =1 (yes) |
| BMI | BMXBMI | |
| <18.5 | ||
| 18.5-24.9 | ||
| 25-29.9 | ||
| ≥30 | ||
| Doctor ever said you were overweight | MCQ080 | =1 (yes) |
| Osteoporosis | OSQ060 | =1 (yes) |
| Ever had thyroid problems | MCQ160M | =1 (yes) |
| Still have thyroid problems | MCQ170M | =1 (yes) |
Abbreviations: BMI, body mass index; COPD, chronic obstructive pulmonary disease; FT4, free thyroxine; HT, hypothyroidism; NHANES, National Health and Nutrition Examination Survey; RX, prescription; SCHIP, State Children’s Health Insurance Program; TSH, thyroid stimulating hormone.
Survey responses may not be mutually exclusive. Where multiple forms of insurance were reported, the hierarchy of payment used by the National Center for Health Statistics in NHANES was employed (Medicare, Medicaid/SCHIP, private insurance, worker's compensation, self-pay, no charge/charity, other, unknown).
Includes emphysema and chronic bronchitis.
Includes coronary heart disease, angina, angina pectoris, and myocardial infarction.