Table 2.
Univariate analysis of factors associated with asthma among leather tannery workers, Karachi, Pakistan, August 2003 to March 2004 (n = 641†)
| Variables | n | OR | 95%CI | p |
| Age | 641 | 1.06 | 1.02, 1.08 | <0.01 |
| Educational status | ||||
| Literate | 377 | 1.00 | - | |
| Illiterate | 264 | 2.45 | 1.47, 4.09 | <0.01 |
| Type of house | ||||
| Pacca | 582 | 1.00 | ||
| Katcha | 57 | 0.78 | 0.30, 2.02 | 0.61 |
| Ethnicity | ||||
| Punjabi | 334 | 1.00 | - | <0.01 |
| Pathan | 211 | 3.32 | 1.91, 5.76 | |
| Others | 91 | 1.18 | 0.49, 2.86 | |
| Place of interview | ||||
| Factory | 194 | 1.00 | ||
| Outside factory | 416 | 2.30 | 1.21, 4.42 | 0.01 |
| House ownership | ||||
| Owned | 262 | 1.00 | - | |
| Rented | 376 | 0.96 | 0.58, 1.59 | 0.96 |
| Smoking status | ||||
| Non-smoker | 455 | 1.00 | - | |
| Ever smoker | 182 | 2.11 | 1.26, 3.51 | 0.04 |
| Naswar use‡ | ||||
| No | 150 | 1.00 | - | |
| Yes | 486 | 2.47 | 1.47, 4.15 | 0.01 |
| Perceived allergy§ | ||||
| No | 152 | 1.00 | - | |
| Yes | 475 | 3.71 | 2.20, 6.27 | <0.01 |
| Working hours per day | 641 | 1.01 | 0.98, 1.05 | 0.47 |
| Exposure to chemicals | ||||
| No | 56 | 1.00 | - | |
| Yes | 583 | 0.69 | 0.31, 1.52 | 0.36 |
| Knowledge about hazards of chemicals | ||||
| No | 33 | 1.00 | - | |
| Yes | 543 | 1.15 | 0.39, 3.40 | 0.80 |
| Glove Use | ||||
| User** | 268 | 1.00 | - | |
| Non-user†† | 373 | 2.93 | 1.25, 4.54 | <0.01 |
| Total duration of work | 641 | 1.08 | 1.04, 1.12 | <0.01 |
| Exhaust fan use | ||||
| No | 127 | 1.00 | - | |
| Yes | 355 | 0.91 | 0.47, 1.75 | 0.78 |
| Air sucker use‡‡ | ||||
| No | 367 | 1.00 | - | |
| Yes | 115 | 0.68 | 0.32, 1.43 | 0.31 |
| Water sucker use§§ | ||||
| No | 411 | 1.00 | - | |
| Yes | 71 | 1.12 | 0.50, 2.49 | 0.41 |
| Provision of gloves | ||||
| No | 122 | 1.00 | - | |
| Yes | 447 | 0.78 | 0.42, 1.42 | 0.42 |
| Provision of masks | ||||
| No | 167 | 1.00 | - | |
| Yes | 402 | 0.88 | 0.51, 1.55 | 0.66 |
| Coverage for health*** | ||||
| No | 437 | 1.00 | - | |
| Yes | 131 | 0.87 | 0.47, 1.58 | 0.64 |
| Pre-placement and regular physical examination | ||||
| No | 415 | 1.00 | - | |
| Yes | 80 | 0.76 | 0.38, 1.55 | 0.56 |
† Total for some of the variables does not add up to 641 due to non-response
‡ Naswar is a mixture of tobacco, chemicals and some herbs usually kept in oral cavity between teeth and lips
§ Perceived allergy to at least one of the following substances: food, metals, chemicals, medicine, dusts or animals
** worker who has at least rarely used gloves during different tanning tasks
†† Worker who has never used gloves
‡‡ An instrument placed close to a work station to drain away polluted air in order to keep a low concentration of pollutants at worksite
§§ An instrument placed close to a workstation producing waste water. It prevents logging and accumulation of harmful waste water
*** Whether workers are offered reimbursements against their health care expenses