Table 1.
Baseline characteristics of 79 899 postmenopausal women enrolled in the Nurses’ Health Study according to use of proton pump inhibitors (PPIs) in 2000. Values are numbers (percentages) unless stated otherwise, and all variables are age adjusted (standardised to the age distribution of the study population)
| Non-user of PPIs (n=74 558) | Regular PPI user (n=5341) | |
|---|---|---|
| Mean (SD) age (years) | 66.6 (6.9) | 67.0 (7.0) |
| Mean (SD) body mass index (kg/m2) | 26.6 (5.2) | 28.2 (5.6) |
| Smoking status*: | ||
| Never | 32 983 (44.3) | 2194 (41.2) |
| Former use ≥10 years | 28 100 (37.7) | 2204 (41.3) |
| Former use <10 years | 6411 (8.6) | 544 (10.2) |
| Current use <15 cigarettes/day | 3399 (4.5) | 202 (3.7) |
| Current use ≥15 cigarettes/day | 3492 (4.7) | 185 (3.4) |
| Missing data† | 173 (0.2) | 12 (0.2) |
| Mean (SD) physical activity (METs-hour/week)‡ | 17.7 (15.6) | 14.5 (13.2) |
| Mean (SD) Alcohol intake (g/day)§ | 5.6 (8.5) | 4.7 (7.7) |
| Mean (SD) Calcium intake (mg/day)§ | 982 (341) | 1001 (347) |
| Use of hormone replacement therapy: | ||
| Current | 32 234 (43.2) | 2570 (48.1) |
| Former or never | 37 920 (50.9) | 2481 (46.5) |
| Missing data† | 4404 (5.9) | 290 (5.4) |
| History of osteoporosis | 22.0 | 31.0 |
| Use of bisphosphonate | 6.0 | 7.0 |
| Use of corticosteroid | 5.0 | 11.0 |
| Use of thiazide | 15.0 | 24.0 |
| Mean (SD) vitamin D intake (IU/day)§ | 443 (265) | 461 (274) |
SD=standard deviation. METs=metabolic equivalents.
*Categories were selected based on prior studies.#_ENREF_19
†The missing data category could not be included in our multivariate models because the numbers of participants in the missing categories were too low. Thus, in our models we carried forward values from prior questionnaires.
‡381 participants did not complete the physical activity assessment. For these participants, we assigned the median value of physical activity derived from the entire cohort.
§1443 did not complete the semi-quantitative food frequency questionnaire. For these participants, we assigned the median value of calcium, alcohol, and vitamin D derived from the entire cohort.