Abstract
Objective
To estimate the prevalence of current asthma and the proportion of asthma that is work-related among health care and non–health care workers.
Methods
We used 2008 and 2010 Behavioral Risk Factor Surveillance System High Risk/Health Care Worker Module and Asthma Call-Back Survey data collected in 35 states and the District of Columbia to estimate prevalence ratios (PRs).
Results
Significantly more health care workers/volunteers than non–health care workers/volunteers with current asthma had asthma attacks (PR = 1.23; 95% confidence interval = 1.03 to 1.46) and asthma symptoms within the past year (PR = 1.07; 95% confidence interval = 1.00 to 1.14). There was no significant difference in the proportion of health care and non–health care workers/volunteers diagnosed with current asthma or work-related asthma.
Conclusions
The results of this study are consistent with previous research showing that health care workers with asthma have higher proportions of asthma attacks than non–health care workers.
Asthma is a chronic disorder of the airways characterized by symptoms of wheezing, coughing, chest tightness, and shortness of breath.1 In 2010, an estimated 15 million working-age (18 to 64 years old) adults in the United States had asthma.2 Many exposures can cause or exacerbate asthma, including those in the workplace.1 Work-related asthma is a subset of asthma that is caused by or exacerbated by work-related factors.3 Among adults with current asthma, an estimated 9.0% have health professional-diagnosed work-related asthma and an additional 37.5% describe their asthma as caused or made worse by workplace exposures.4
In 2008, there were 13.3 million people employed in private-sector health care in the United States.5 Population-based research has shown that among adults with lifetime asthma, health care workers have a higher prevalence of asthma attacks than non–health care workers.6 Case-based surveillance systems in four states found that among work-related asthma cases, health care workers were over-represented compared with the percentage expected on the basis of workforce composition.7
To date, little population-based information exists on work-related asthma in US health care workers. To estimate the prevalence of current asthma and the proportion of asthma that is work-related among health care workers, we analyzed 2008 and 2010 Behavioral Risk Factor Surveillance System (BRFSS) High Risk/Health Care Worker Module and Asthma Call-Back Survey data collected in 35 states and the District of Columbia (DC) from persons aged 18 years or more who were employed in the year before the interview.
METHODS
Data Source
The BRFSS is an ongoing, state-based, telephone survey of noninstitutionalized adults in the United States that collects information on health risk behaviors, health care access, and disease status.8 To identify health care workers at risk for influenza, the High Risk/Health Care Worker Module was administered as part of BRFSS in select states in 2008 and 2010. The Asthma Call-Back Survey was administered within 2 weeks of the BRFSS interview to a subset of respondents who indicated that they had ever had asthma.9 See the footnote in Table 1 for a list of states conducting the High Risk/Health Care Module and Asthma Call-Back Survey in 2008 and 2010. The Council of American Survey and Research Organizations median response rate among the three participating states in 2008 was 48.2% for BRFSS and 50.6% for the Asthma Call-Back Survey, and for the 35 states and the DC participating in 2010 the median response rate was 52.0% for BRFSS and 49.8% for the Asthma Call-Back Survey. The BRFSS has surveillance exemption from the Institutional Review Board at the Centers for Disease Control and Prevention. Participating states are subject to state-specific Institutional Review Board requirements.
TABLE 1.
2008 and 2010 Asthma Call-Back Survey Questions Used in This Report*
| Definition | Asthma Call-Back Survey Question |
|---|---|
| Lifetime asthma | Have you ever been told by a doctor, nurse, or other health professional that you had asthma?† |
| Current asthma | Do you still have asthma?† |
| Age of asthma onset | How old were you when you were first told by a doctor or other health professional that you had asthma?‡ |
| Asthma attack | During the past 12 mo, have you had an episode of asthma or asthma attack?† |
| Activity limitation because of asthma | During the past 12 mo, how many days were you unable to work or carry out your usual activities because of your asthma?§ |
| Time since last talked to the health professional about asthma | How long has it been since you last talked to a doctor or other health professional about your asthma?|| |
| Time since last took asthma medication | How long has it been since you last took asthma medication?¶ |
| Time since last had asthma symptoms | How long has it been since you last had any symptoms of asthma?¶ |
| Routine checkup for asthma | During the past 12 mo, how many times did you see a doctor or other health professional for a routine checkup for your asthma?# |
| Urgent treatment for worsening asthma | During the past 12 mo, how many times did you see a doctor or other health professional for urgent treatment of worsening asthma symptoms or for an asthma episode or attack?# |
| Asthma-related emergency room visit | During the past 12 mo, have you had to visit an emergency room or urgent care center because of your asthma?† |
| Asthma-related hospitalization | During the past 12 mo, have you had to stay overnight in a hospital because of your asthma?† |
| Health professional-diagnosed work-related asthma | Were you ever told by a doctor or other health professional that your asthma was related to any job you ever had?† |
| Possible work-related asthma** | Was your asthma caused by chemicals, smoke, fumes, or dust in your current job?† Was your asthma caused by chemicals, smoke, fumes, or dust in any previous job you ever had?† Is your asthma made worse by chemicals, smoke, fumes, or dust in your current job?† Was your asthma made worse by chemicals, smoke, fumes, or dust in any previous job you ever had?† |
| Change or quit job because of asthma | Did you ever change or quit a job because chemicals, smoke, fumes, or dust caused your asthma or made your asthma worse?† |
In 2008, three states (Florida, Hawaii, and New York) and in 2010, 35 states (Alabama, Arizona, California, Connecticut, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Louisiana, Maine, Maryland, Massachusetts, Michigan, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, Texas, Utah, Washington, West Virginia, and Wisconsin) and the District of Columbia conducted the High Risk/Health Care Module and the Asthma Call-Back Survey.
Response options include “yes” or “no.”
Response options include numeric age in years.
Response options include the numeric number of days.
Response options include “within the past year,” “1 year to less than 3 years ago,” “3 to 5 years ago,” and “more than 5 years ago.”
Response options include “less than 1 day ago,” “1 to 6 days ago,” “1 week to less than 3 months ago,” “3 months to less than 1 year ago,” “1 year to less than 3 years ago,” “3 years to 5 years ago,” and “more than 5 years ago.”
Response options include the numeric number of times.
Among respondents who did not have health professional-diagnosed work-related asthma (ie, responded “no” or “do not know”).
Study Population and Definitions
For this analysis, the study population included adults who had been employed in the year before the interview, that is, those who answered “employed for wages,” “self-employed,” or “out of work for less than 1 year” to the question “Are you currently … employed for wages, self-employed, out of work for more than 1 year, out of work for less than 1 year, a homemaker, a student, retired, or unable to work?” Health care workers/volunteers were persons who answered “yes” to the question “Do you currently volunteer or work in a hospital, medical clinic, doctor’s office, dentist’s office, nursing home or some other health care facility? This includes part-time and unpaid work in a health care facility as well as professional nursing care provided in the home.”
Questions pertaining to asthma history, asthma-related health care utilization, and work-related asthma used in this report are shown in Table 1. We defined non–work-related asthma on the basis of a “no” response to all of the health professional-diagnosed and possible work-related asthma questions in Table 1.
Statistical Analysis
We used SAS® software version 9.3 (SAS Institute Inc, Cary, NC) survey procedures and SUDAAN® Release 10.0.1 software (Research Triangle Institute, Research Triangle Park, NC) to account for the complex survey design. Data were weighted to account for nonresponse differences in the sample and the unequal probability of sample selection in order to produce representative estimates. For states that administered the High Risk/Health Care Module to a subset of the state sample in one version of the questionnaire, the Asthma Call-Back Survey final weight was proportionately adjusted based on the value of the BRFSS core final weight. For the three states with 2 years of data, weights based on the proportionate distribution of the sample completing the High Risk/Health Care Module and the Asthma Call-Back Survey between the 2 years were calculated.
We compared health care workers/volunteers and non–health care workers/volunteers using multivariate logistic regression. All multivariate associations were adjusted for age (continuous), sex, annual household income (three categories: <$25,000, $25,000 to $49,999, and ≥$50,000), and health insurance status (two categories: insured and not insured) because these variables were independently associated with both employment as a health care worker/volunteer and current asthma status.
RESULTS
Adults Employed in the Year Before the Interview
A total of 182,825 (representing an estimated 115.6 million) adults in the 35 states and the DC that administered the BRFSS High Risk/Health Care Worker Module in 2008 and 2010 were employed in the year before the interview. Of adults employed in the year before the interview, 7.5% had current asthma and 13.3% were health care workers/volunteers (Table 2).
TABLE 2.
Characteristics of Adults Employed in the Year Before the Interview
| Characteristics | Total
|
Health Care Workers/ Volunteers (N = 15,285) %‡ (95% CI) | Non–Health Care Workers/ Volunteers (N = 84,673) %‡ (95% CI) | Unadjusted PR (95% CI) | Adjusted PR§ (95% CI) | ||
|---|---|---|---|---|---|---|---|
| N* | Weighted N (in Thousands)† | %‡ (95% CI) | |||||
| Age, yr | |||||||
| 18–44 | 63,594 | 65,180 | 56.7 (56.3–57.1) | 54.8 (53.4–56.2) | 57.6 (57.0–58.2) | 0.95 (0.93–0.98) | 1.00 (0.97–1.03) |
| ≥45 | 117,461 | 49,746 | 43.3 (42.9–43.7) | 45.2 (43.8–46.6) | 42.4 (41.8–43.0) | 1.07 (1.03–1.10) | 1.01 (0.97–1.05) |
| Sex | |||||||
| Male | 78,213 | 63,390 | 54.8 (54.4–55.3) | 30.0 (28.5–31.5) | 59.0 (58.3–59.6) | 0.51 (0.48–0.54) | 0.51 (0.49–0.54) |
| Female | 104,612 | 52,210 | 45.2 (44.7–45.6) | 70.0 (68.5–71.5) | 41.0 (40.4–41.7) | 1.71 (1.66–1.75) | 1.72 (1.67–1.77) |
| Race/ethnicity | |||||||
| White, non-Hispanic | 140,378 | 77,067 | 67.4 (66.9–67.9) | 66.1 (64.6–67.6) | 65.1 (64.4–65.8) | 1.02 (0.99–1.04) | 0.97 (0.94–0.99) |
| Other | 40,305 | 37,268 | 32.6 (32.1–33.1) | 33.9 (32.4–35.4) | 34.9 (34.2–35.6) | 0.97 (0.92–1.02) | 1.06 (1.01–1.11) |
| Education level | |||||||
| High school or less | 55,393 | 36,566 | 31.7 (31.2–32.1) | 18.9 (17.8–20.1) | 34.1 (33.5–34.8) | 0.56 (0.52–0.59) | 0.67 (0.63–0.71) |
| More than high school | 127,140 | 78,871 | 68.3 (67.9–68.8) | 81.1 (79.9–82.2) | 65.9 (65.2–66.5) | 1.23 (1.21–1.25) | 1.16 (1.14–1.18) |
| Annual household income, $ | |||||||
| <25,000 | 27,677 | 18,711 | 17.8 (17.4–18.2) | 14.0 (12.9–15.2) | 19.2 (18.6–19.8) | 0.73 (0.67–0.80) | 0.83 (0.77–0.89) |
| 25,000–49,999 | 42,445 | 23,586 | 22.4 (22.0–22.8) | 21.1 (19.9–22.3) | 22.7 (22.1–23.3) | 0.93 (0.87–0.99) | 0.92 (0.86–0.98) |
| ≥50,000 | 96,128 | 63,002 | 59.8 (59.4–60.3) | 64.9 (63.4–66.4) | 58.1 (57.4–58.8) | 1.12 (1.09–1.15) | 1.09 (1.06–1.12) |
| Health insurance | |||||||
| Yes | 160,053 | 97,437 | 84.5 (84.1–84.9) | 90.4 (89.5–91.3) | 83.2 (82.6–83.8) | 1.09 (1.07–1.10) | 1.05 (1.03–1.06) |
| No | 22,437 | 17,849 | 15.5 (15.1–15.9) | 9.6 (8.7–10.5) | 16.8 (16.2–17.4) | 0.57 (0.52–0.63) | 0.76 (0.70–0.84) |
| Smoking status | |||||||
| Current | 29,754 | 19,378 | 16.9 (16.6–17.3) | 13.1 (12.2–14.1) | 17.1 (16.6–17.7) | 0.77 (0.71–0.83) | 0.90 (0.83–0.97) |
| Former | 47,481 | 25,278 | 22.1 (21.7–22.4) | 20.9 (19.7–22.1) | 22.2 (21.7–22.8) | 0.94 (0.88–1.00) | 1.00 (0.94–1.06) |
| Never | 104,553 | 69,806 | 61.0 (60.6–61.4) | 66.0 (64.6–67.4) | 60.6 (60.0–61.3) | 1.09 (1.06–1.12) | 1.03 (1.00–1.06) |
| Lifetime asthma | |||||||
| Yes | 22,711 | 14,345 | 12.4 (12.1–12.7) | 13.3 (12.3–14.3) | 12.1 (11.7–12.5) | 1.10 (1.01–1.19) | 1.00 (0.91–1.09) |
| No | 159,714 | 101,039 | 87.6 (87.3–87.9) | 86.7 (85.7–87.7) | 87.9 (87.5–88.3) | 0.99 (0.97–1.00) | 1.00 (0.99–1.01) |
| Current asthma | |||||||
| Yes | 14,367 | 8,595 | 7.5 (7.2–7.7) | 8.8 (8.0–9.6) | 7.0 (6.7–7.3) | 1.26 (1.14–1.40) | 1.06 (0.95–1.18) |
| No | 167,449 | 106,429 | 92.5 (92.3–92.8) | 91.2 (90.4–92.0) | 93.0 (92.7–93.3) | 0.98 (0.97–0.99) | 1.00 (0.99–1.00) |
| Total | 182,825 | 115,600 | 13.3 (12.9–13.7) | 86.7 (86.3–87.1) | |||
Unweighted sample size. The numbers for characteristic subgroups may not add to total because of missing values. The sample size for health care workers/volunteers and non–health care workers/volunteers does not sum to total because only a subset of respondents completed both the High Risk/Health Care Worker Module and Asthma Call-Back Survey.
Weighted to the state population using the survey sample weights for each BRFSS participant.
Results presented as weighted average annual estimate.
Prevalence ratio, adjusted for age, sex, annual household income, and health insurance status.
BRFSS, Behavioral Risk Factor Surveillance System; CI, confidence interval; PR, prevalence ratio.
After adjusting for covariates, health care workers/volunteers were more likely than non–health care workers/volunteers to be female (prevalence ratio [PR] = 1.72; 95% confidence interval [CI] = 1.67 to 1.77), to be other race/ethnicity (PR = 1.06; 95% CI = 1.01 to 1.11), to have more than a high school education (PR = 1.16; 95% CI = 1.14 to 1.18), to have an annual household income greater than or equal to $50,000 (PR = 1.09; 95% CI = 1.06 to 1.12), and to have health insurance (PR = 1.05; 95% CI = 1.03 to 1.06). In addition, health care workers/volunteers had a significantly higher prevalence of current asthma than non–health care workers/volunteers (8.8% vs 7.0%, respectively). Nevertheless, after adjusting for covariates, the association was not significant (PR = 1.06; 95% CI = 0.95 to 1.18) (Table 2).
Adults With Current Asthma Employed in the Year Before the Interview
Most adults with current asthma employed in the year before the interview were aged 18 to 44 years (58.0%), female (59.6%), non-Hispanic white (74.6%), had more than a high school education (73.6%), had an annual household income of $50,000 or more (58.7%), had health insurance (86.0%), and were never smokers (60.3%) (Table 3). After adjusting for covariates, health care workers/volunteers with current asthma were more likely to be 18 to 44 years old, female, and former smokers and less likely to have an annual household income of less than $25,000 than non–health care workers/volunteers with current asthma (Table 3).
TABLE 3.
Characteristics of Adults With Current Asthma Employed in the Year Before the Interview
| Characteristics | Total
|
Health Care Workers/ Volunteers (N = 570) %‡ (95% CI) | Non–Health Care Workers/ Volunteers (N = 2437) %‡ (95% CI) | Unadjusted PR (95% CI) | Adjusted PR§ (95% CI) | ||
|---|---|---|---|---|---|---|---|
| N* | Weighted N (in Thousands)† | %‡ (95% CI) | |||||
| Age, yr | |||||||
| 18–44 | 1,613 | 5,899 | 58.0 (55.2–60.7) | 66.6 (58.8–74.5) | 56.6 (52.6–60.6) | 1.18 (1.02–1.36) | 1.19 (1.03–1.38) |
| ≥45 | 3,494 | 4,279 | 42.0 (39.3–44.8) | 33.4 (25.5–41.2) | 43.4 (39.4–47.4) | 0.77 (0.59–1.00) | 0.76 (0.58–0.99) |
| Sex | |||||||
| Male | 1,507 | 4,114 | 40.4 (37.3–43.4) | 17.1 (10.0–24.2) | 42.9 (38.6–47.3) | 0.40 (0.26–0.61) | 0.34 (0.22–0.51) |
| Female | 3,621 | 6,082 | 59.6 (56.6–62.7) | 82.9 (75.8–90.0) | 57.1 (52.7–61.4) | 1.45 (1.29–1.63) | 1.54 (1.38–1.72) |
| Race/ethnicity | |||||||
| White, non-Hispanic | 4,087 | 7,552 | 74.6 (71.9–77.4) | 76.8 (68.9–84.7) | 74.0 (70.0–78.0) | 0.60 (0.37–0.96) | 1.00 (0.88–1.14) |
| Other | 1,009 | 2,565 | 25.4 (22.6–28.1) | 23.2 (15.3–31.1) | 26.0 (22.0–30.0) | 1.16 (1.04–1.29) | 1.00 (0.69–1.44) |
| Education level | |||||||
| High school or less | 1,267 | 2,690 | 26.4 (23.7–29.1) | 16.9 (9.3–24.4) | 28.2 (24.2–32.2) | 1.04 (0.92–1.17) | 0.81 (0.55–1.20) |
| More than high school | 3,855 | 7,496 | 73.6 (70.9–76.3) | 83.1 (75.6–90.7) | 71.8 (67.8–75.8) | 0.89 (0.61–1.30) | 1.07 (0.96–1.19) |
| Annual household income, $ | |||||||
| <25,000 | 850 | 1,505 | 16.1 (13.9–18.3) | 8.4 (5.0–11.9) | 18.2 (14.7–21.8) | 0.46 (0.29–0.73) | 0.52 (0.34–0.80) |
| 25,000–49,999 | 1,249 | 2,350 | 25.1 (22.5–27.8) | 27.8 (18.9–36.7) | 26.0 (22.0–29.9) | 1.07 (0.75–1.54) | 1.13 (0.79–1.62) |
| ≥50,000 | 2,660 | 5,490 | 58.7 (55.7–61.8) | 63.8 (54.4–73.1) | 55.8 (51.4–60.3) | 1.14 (0.97–1.35) | 1.09 (0.92–1.29) |
| Health insurance | |||||||
| Yes | 4,584 | 8,751 | 86.0 (83.7–88.3) | 93.5 (90.6–96.5) | 84.8 (81.0–88.5) | 1.10 (1.05–1.17) | 1.04 (0.98–1.10) |
| No | 538 | 1,426 | 14.0 (11.7–16.3) | 6.5 (3.5–9.4) | 15.2 (11.5–19.0) | 0.43 (0.25–0.72) | 0.75 (0.47–1.21) |
| Smoking status | |||||||
| Current | 738 | 1,628 | 16.0 (13.7–18.3) | 15.2 (7.7–22.6) | 16.2 (12.9–19.6) | 0.93 (0.55–1.60) | 1.23 (0.77–1.96) |
| Former | 1,470 | 2,420 | 23.8 (21.4–26.2) | 27.0 (18.6–35.3) | 22.4 (19.0–25.8) | 1.20 (0.85–1.71) | 1.39 (1.00–1.94) |
| Never | 2,905 | 6,137 | 60.3 (57.3–63.2) | 57.9 (48.2–67.5) | 61.4 (57.2–65.5) | 0.94 (0.79–1.13) | 0.81 (0.65–1.00) |
| Age of asthma onset, yr | |||||||
| <18 | 1,801 | 4,678 | 48.4 (45.3–51.4) | 42.8 (33.1–52.5) | 50.0 (45.6–54.4) | 0.85 (0.67–1.09) | 0.95 (0.80–1.15) |
| ≥18 | 3,079 | 4,991 | 51.6 (48.6–54.7) | 57.2 (47.5–66.9) | 50.0 (45.6–54.4) | 1.15 (0.95–1.40) | 1.05 (0.88–1.24) |
| Asthma control level|| | |||||||
| Well controlled | 2,934 | 6,188 | 60.7 (57.8–63.6) | 56.3 (46.3–66.4) | 63.1 (59.2–67.0) | 0.89 (0.74–1.08) | 0.91 (0.75–1.11) |
| Not well controlled | 1,292 | 2,355 | 23.1 (20.7–25.5) | 27.5 (17.9–37.1) | 21.8 (18.6–25.0) | 1.26 (0.86–1.86) | 1.25 (0.85–1.83) |
| Very poorly controlled | 900 | 1,653 | 16.2 (14.1–18.3) | 16.1 (8.3–24.0) | 15.1 (12.3–17.9) | 1.07 (0.63–1.82) | 0.99 (0.60–1.65) |
| Asthma attack¶ | |||||||
| Yes | 2,505 | 5,085 | 50.1 (47.1–53.1) | 64.9 (56.2–73.6) | 49.0 (44.7–53.3) | 1.32 (1.12–1.56) | 1.23 (1.03–1.46) |
| No | 2,590 | 5,064 | 49.9 (46.9–52.9) | 35.1 (26.4–43.8) | 51.0 (46.7–55.3) | 0.69 (0.53–0.90) | 0.77 (0.59–1.00) |
| Routine checkup for asthma¶ | |||||||
| Yes | 3,026 | 6,312 | 62.1 (59.2–65.0) | 62.0 (52.1–71.9) | 63.8 (59.9–67.7) | 0.97 (0.82–1.16) | 1.07 (0.92–1.25) |
| No | 2,069 | 3,849 | 37.9 (35.0–40.8) | 38.0 (28.1–47.9) | 36.2 (32.3–40.1) | 1.05 (0.79–1.39) | 0.89 (0.66–1.20) |
| Urgent treatment for worsening asthma¶ | |||||||
| Yes | 1,087 | 2,062 | 20.3 (18.0–22.6) | 25.6 (17.4–33.8) | 19.6 (16.3–22.9) | 1.31 (0.90–1.88) | 1.08 (0.75–1.57) |
| No | 4,026 | 8,108 | 79.7 (77.4–82.0) | 74.4 (66.2–82.6) | 80.4 (77.1–83.7) | 0.93 (0.82–1.04) | 0.98 (0.88–1.09) |
| Asthma-related emergency room visit¶ | |||||||
| Yes | 508 | 1,146 | 11.3 (9.4–13.1) | 18.6 (10.7–26.6) | 10.2 (7.8–12.6) | 1.83 (1.10–3.07) | 1.53 (0.88–2.65) |
| No | 4,612 | 9,038 | 88.7 (86.9–90.6) | 81.4 (73.4–89.3) | 89.8 (87.4–92.3) | 0.91 (0.82–1.01) | 0.93 (0.84–1.04) |
| Asthma-related hospitalization¶ | |||||||
| Yes | 80 | 89 | 0.9 (0.6–1.2) | NR (NR) | 0.8 (0.4–1.1) | NR (NR) | NR (NR) |
| No | 5,045 | 10,096 | 99.1 (98.8–99.4) | 99.5 (99.0–99.9) | 99.2 (98.9–99.6) | NR (NR) | NR (NR) |
| Activity limitation because of asthma¶ | |||||||
| At least 1 d | 1,312 | 2,712 | 27.0 (24.4–29.6) | 34.5 (25.3–43.7) | 27.1 (23.3–30.9) | 1.27 (0.94–1.73) | 1.19 (0.87–1.62) |
| No days | 3,749 | 7,340 | 73.0 (70.4–75.6) | 65.5 (56.3–74.7) | 72.9 (69.1–76.7) | 0.90 (0.77–1.05) | 0.93 (0.80–1.08) |
| Time since last talked to the health professional about asthma | |||||||
| Within past year | 3,489 | 6,599 | 64.9 (61.9–67.8) | 69.4 (60.7–78.2) | 62.5 (58.1–66.8) | 1.11 (0.96–1.28) | 0.99 (0.84–1.15) |
| 1 yr ago or more | 1,620 | 3,572 | 35.1 (32.2–38.1) | 30.6 (21.8–39.3) | 37.5 (33.2–41.9) | 0.82 (0.60–1.11) | 1.03 (0.78–1.35) |
| Time since last took asthma medication | |||||||
| Within past year | 4,179 | 8,034 | 78.9 (76.3–81.6) | 85.4 (78.8–92.0) | 77.8 (73.8–81.9) | 1.10 (1.00–1.20) | 1.04 (0.94–1.16) |
| 1 yr ago or more | 933 | 2,142 | 21.1 (18.4–23.7) | 14.6 (8.0–21.2) | 22.2 (18.1–26.2) | 0.66 (0.41–1.07) | 0.84 (0.52–1.35) |
| Time since last had asthma symptoms | |||||||
| Within past year | 4,425 | 8,710 | 86.2 (84.0–88.3) | 90.6 (85.6–95.5) | 85.4 (82.3–88.5) | 1.06 (0.99–1.13) | 1.07 (1.00–1.14) |
| 1 yr ago or more | 639 | 1,400 | 13.8 (11.7–16.0) | 9.4 (4.5–14.4) | 14.6 (11.5–17.7) | 0.65 (0.37–1.14) | NR (NR) |
| Advised to change things in environment | |||||||
| Yes | 2,141 | 4,564 | 45.1 (42.1–48.2) | 60.2 (51.5–68.8) | 43.8 (39.6–48.1) | 1.37 (1.15–1.64) | 1.26 (1.04–1.52) |
| No | 2,962 | 5,547 | 54.9 (51.8–57.9) | 39.8 (31.2–48.5) | 56.2 (51.9–60.4) | 0.71 (0.56–0.90) | 0.79 (0.63–0.99) |
| Work-related asthma status | |||||||
| Work-related asthma | 440 | 813 | 8.0 (6.4–9.6) | 7.5 (2.2–12.9) | 7.9 (5.7–10.2) | NR (NR) | NR (NR) |
| Possible work-related asthma | 2,001 | 3,797 | 37.5 (34.7–40.3) | 40.2 (30.6–49.8) | 38.3 (34.3–42.4) | 1.05 (0.80–1.36) | 1.06 (0.81–1.37) |
| Non–work-related asthma | 2,668 | 5,513 | 54.5 (51.5–57.4) | 52.3 (42.4–62.2) | 53.7 (49.5–58.0) | 0.97 (0.79–1.20) | 0.98 (0.80–1.20) |
| Change or quit job because of asthma | |||||||
| Yes | 329 | 661 | 6.5 (4.9–8.1) | NR (NR) | 7.1 (4.9–9.3) | 1.39 (0.61–3.17) | NR (NR) |
| No | 4,771 | 9,506 | 93.5 (91.9–95.1) | 90.2 (82.7–97.7) | 92.9 (90.7–95.1) | 0.97 (0.89–1.06) | 0.96 (0.87–1.05) |
| Total | 5,128 | 10,196 | 19.1 (15.8–22.4) | 3.9 (2.4–5.4) | |||
Unweighted sample size. The numbers for characteristic subgroups may not add to total because of missing values. The sample size for health care workers/volunteers and non–health care workers/volunteers does not sum to total because only a subset of respondents completed both the High Risk/Health Care Worker Module and Asthma Call-Back Survey.
Weighted to the state population using the survey sample weights for each Asthma Call-Back Survey participant.
Results presented as weighted average annual estimate.
Prevalence ratio, adjusted for age, sex, annual household income, and health insurance status.
On the basis of the National Asthma Education and Prevention Program “Expert Panel Report 3 (EPR-3): Guidelines for the Diagnosis and Management of Asthma” criteria using responses to questions on asthma symptoms, nighttime awakenings, and rescue medication use.1
In the past 12 months.
CI, confidence interval; NR, not reportable, relative standard error ≥30%; PR, prevalence ratio.
Among adults with current asthma employed in the year before the interview, higher proportions of health care workers/volunteers than non–health care workers/volunteers have had an asthma attack in the past year (adjusted PR = 1.23; 95% CI = 1.03 to 1.46), had asthma symptoms within the past year (adjusted PR = 1.07; 95% CI = 1.00 to 1.14), and been advised to change things in their home, work, or school environment (adjusted PR = 1.26; 95% CI = 1.04 to 1.52). Nevertheless, health care workers/volunteers with current asthma did not differ from non–health care workers/volunteers with current asthma in education level, health insurance status, age of asthma onset, asthma control level, the proportion of adults that had routine checkups for their asthma, urgent treatment for worsening asthma, asthma-related emergency room visits, activity limitation because of asthma, the time since they last talked to a health professional about their asthma, the time since they last took asthma medication, and work-related asthma status (Table 3).
DISCUSSION
The results of this cross-sectional study are consistent with previous research showing that health care workers have higher prevalence of current asthma and that health care workers with current asthma have higher proportions of asthma attacks than non–health care workers.6,10 We found that health care workers/volunteers had a higher prevalence of current asthma than non–health care workers/volunteers (but this difference was eliminated when adjusting for covariates), and that there was no difference in the proportion of work-related asthma between health care workers/volunteers and non–health care workers/volunteers with current asthma. This population-based study is one of the first in the United States to evaluate the proportion of asthma that is diagnosed as work-related among health care workers.
Our findings are consistent with the research by Arif and colleagues11,12 that have found the health care industry and health-related occupations are not at an increased risk for work-related asthma. In their study, the authors examined work-related asthma through symptoms such as wheezing, whistling, stuffy, itchy, or runny nose among adults with asthma in different industries and found that health care workers did not have an elevated risk for work-related asthma.11 Previous population-based research also found that health-related occupations did not have higher prevalence of work-related asthma than referent groups of management, secretarial, and clerical-related occupations.12 Nevertheless, this past research used National Health and Nutrition Examination Survey data that did not have a direct question assessing whether the respondent had health professional-diagnosed work-related asthma but rather relied on a question assessing whether a respondent with asthma had symptoms brought on by the work environment.11,12 In addition, the previous studies categorized industry and occupation on the basis of the respondent’s longest-held job, although we used the respondent’s current job or volunteer activity.11,12
Nonetheless, many studies have found that health care workers are at an increased risk for both asthma and work-related asthma.7,10,13–15 In a study of the employed population in Finland, Karjalainen and colleagues13 estimated the incidence of asthma to be significantly higher in medical and nursing work than in administrative work (relative risk = 1.1 to 1.2). Using data from the European Community Respiratory Health Survey, they found that nurses were at an increased risk for new-onset asthma compared with professional, clerical, and administrative occupations (odds ratio = 2.22; 95% CI = 1.25 to 3.96).14 In addition, a population-based study in the United States found that the prevalence of asthma was higher in white females employed in the health care industry than in industries with office employment.10
In four state-based sentinel work-related asthma surveillance systems, health care workers were overrepresented (16%) compared with health care workers as a percentage of the total workforce (8%).7 Health care workers were also more likely to have work-aggravated asthma than non–health care workers (23% vs 18%).7 These findings may be due to differential diagnosis, reporting, and case confirmation in health care workers.7 In a Canadian study of workers’ compensation claims for work-exacerbated and occupational asthma, the most frequent industry for work-exacerbated asthma was the health care industry, and the rate of allowed claims for work-exacerbated asthma was significantly greater in health care than in other industries.15
The roles of health care workers and the specific occupational tasks they perform vary widely.16 Certain exposures may be widespread in the health care industry including cleaning products, latex, glutaraldehyde, and formaldehyde.7,14,17–20 Mirabelli and colleagues16 found that nursing and health care workers did not have an elevated risk for developing new-onset asthma compared with other workers. Nevertheless, the authors did find an elevated risk of asthma among nursing and health care workers who reported certain occupational exposures such as using ammonia or bleach cleaning products more than once per week and among particular occupational groups such as hospital technicians and personal care providers in institutional environments.16 The BRFSS was not designed to collect information on specific occupational subgroups and exposures.
The results of this study suggest that the age of health care workers/volunteers and non–health care workers/volunteers does not differ. Nevertheless, among those with current asthma, health care workers/volunteers are more likely to be 18 to 44 years old than non–health care workers/volunteers. The reasons for the difference are not apparent. One possibility is the “healthy worker survivor effect” where workers self-select themselves out of jobs with high exposures—a phenomenon that may be more likely to occur with longer duration of employment.21,22
This study is subject to some limitations. Because of the cross-sectional survey design, we were not able to assess whether the respondents’ asthma and work-related asthma were caused or made worse by workplace exposures specific to the health care or any other industry. The survey was not designed to collect detailed information on job history or exposure. In addition, it was not possible to analyze the data separately for workers and volunteers. Nevertheless, in 2013, the Centers for Disease Control and Prevention will sponsor a BRFSS optional module designed to collect respondents’ current employment information such as industry and occupation. This information, when available, may allow for further detailed analysis of asthma and work-related asthma among workers in the health care industry. Finally, the results of this study are not representative of nonparticipating states or the entire US population.
To our knowledge, this population-based study is the first to evaluate the proportion of asthma that is diagnosed as work-related among health care workers in the United States. These results suggest that health care workers/volunteers with asthma have higher prevalence of asthma attacks than non–health care workers/volunteers. Future studies should examine factors associated with work-related asthma in health care workers.
Acknowledgments
The authors thank Dr Michael Hodgson, Veterans Affairs Medical Center, Washington, DC, and Dr Susan McCrone, West Virginia University School of Nursing, Morgantown, West Virginia, for their helpful comments. The authors also thank the BRFSS state coordinators for their assistance in collecting the data used in this analysis.
Footnotes
The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. No financial disclosures were reported by the authors of this article.
The authors declare no conflicts of interest.
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