Variable definitions and sample descriptive statistics
| Variable | Definition | Categories | n (%) or mean (SD) |
| Polypharmacy | Use of five or more medications | Yes | 1654 (25.8%) |
| No | 4746 (74.2%) | ||
| Extreme polypharmacy | Use of 10 or more medications | Yes | 254 (4.0%) |
| No | 6146 (96.0%) | ||
| Polypharmacy excluding supplements | Use of five or more medications, excluding supplements | Yes | 1469 (23.0%) |
| No | 4931 (77.0%) | ||
| Extreme polypharmacy excluding supplements | Use of 10 or more medications, excluding supplements | Yes | 187 (2.9%) |
| No | 6213 (97.1%) | ||
| Payment method | How was last prescription paid for? | OOP | 2281 (35.6%) |
| MC | 2869 (44.8%) | ||
| DPS | 706 (11.0%) | ||
| PHI | 146 (2.3%) | ||
| LTI | 286 (4.5%) | ||
| Missing | 112 (1.8%) | ||
| Age | Respondent’s age at time of interview | Years | 66.4 (±8.9) |
| Sex | Sex of respondent | Male | 2825 (44.1%) |
| Female | 3575 (55.9%) | ||
| Education | Highest level of education achieved | Primary | 1623 (25.4%) |
| Secondary | 2548 (39.8%) | ||
| Higher | 2228 (34.8%) | ||
| Missing | 1 (0.02%) | ||
| Employment | Current employment status | Employed | 2111 (33.0%) |
| Retired | 2907 (45.4%) | ||
| Other | 1371 (21.4%) | ||
| Missing | 11 (0.2%) | ||
| Smoking status | Is respondent a current smoker? | Yes | 821 (12.8%) |
| No | 5573 (87.1%) | ||
| Missing | 6 (0.1%) | ||
| Obesity | Is respondent’s BMI >30 kg/m2? | Yes | 1368 (21.4%) |
| No | 4809 (75.1%) | ||
| Missing | 223 (3.5%) | ||
| Self-rated health | Respondent’s rating of own health | Excellent | 910 (14.2%) |
| Very good | 2140 (33.4%) | ||
| Good | 2187 (34.2%) | ||
| Fair | 952 (14.9%) | ||
| Poor | 210 (3.3%) | ||
| Missing | 1 (0.02%) | ||
| Chronic illness | Does the respondent have any long-term illness or disability? | Yes | 2718 (42.5%) |
| No | 3678 (57.5%) | ||
| Missing | 4 (0.1%) | ||
| Primary care usage | How many visits to GP in the last year? | None | 532 (8.3%) |
| 1–4 | 4261 (66.6%) | ||
| 5–9 | 1018 (15.9%) | ||
| 10–14 | 448 (7.0%) | ||
| 15+ | 128 (2.0%) | ||
| Missing | 13 (0.2%) | ||
| Secondary care usage | How many outpatient visits in the last year? | None | 3606 (56.3%) |
| 1 | 1173 (18.3%) | ||
| 2+ | 1610 (25.2%) | ||
| Missing | 11 (0.2%) |
Source: Analysis of The Irish Longitudinal Study on Aging (TILDA) wave 3 data.
BMI, body mass index; DPS, drugs payment scheme; GP, general practitioner; LTI, long-term illness; MC, medical card; OOP, out of pocket; PHI, private health insurance.