It is well known that prehospital emergency medical services (EMS) staff often experience pain (Imani et al, 2018; Möckel et al, 2021). In addition, the EMS Health Study, which included a total of 2313 prehospital EMS staff from Germany, showed that asthma and allergies frequently occur among them. For example, the prevalence of asthma (including allergic asthma) over 12 months in female participants aged 18-29 years was 12.7%, which is 1.72 times higher than in women of the same age in the general German population (Mockel et al, 2022).
International studies have also reported a higher risk of asthma and allergies in health professionals (McHugh et al, 2010; Ghosh et al, 2013; Boudinar et al, 2021). A longitudinal study found that homebased caregivers had 2.1-times higher odds of developing asthma (Ghosh et al, 2013). In addition, a study of French dentists indicated a prevalence of allergies of 50.3%, with work-associated allergies affecting 13.4% (Boudinar et al, 2021).
According to data from the GEDA study (Gesundheit in Deutschland aktuell/German Health Update), one of the largest health monitoring studies on the general German population, the 12-month prevalence of asthma, including allergic asthma, in the general German population is 8.0% and that of allergies, excluding allergic asthma, is 30.9% (Heidemann et al, 2021).
Factors known to promote the occurrence of asthma and allergies include chemical irritants such as disinfectants, reduced exposure to microorganisms including pathogens and altered intestinal flora, for example because of changes in lifestyle factors including diet (Schmitz et al, 2017; Steppuhn et al, 2017). Furthermore, stress can increase the risk of asthma (Lietzen et al, 2011). A study with Italian nurses indicated that 21.8% showed glove-related symptoms (Filon and Radman, 2006).
Many of the factors mentioned above apply to the everyday working life of prehospital EMS staff in Germany. However, no in-depth analyses to identify factors associated with allergies and asthma in prehospital EMS staff have been carried out. Therefore, the aim of this analysis was to identify factors associated with the occurrence of asthma and allergies in prehospital EMS staff from Germany over a 12-month period, based on data from the EMS Health Study.
Methods
Study design
The EMS Health Study was a nationwide, crosssectional, self-reporting online survey examination of physician and non-physician prehospital EMS staff, conducted between 19 May 19 and 1 June 2021.
The link to the survey was distributed via the German Society for Paramedic Sciences (Deutsche Gesellschaft für Rettungswissenschaften), in online groups for EMS staff and by mailing the survey link to randomly selected rescue stations, responsible county agencies and EMS organisations.
Participation in this research was voluntary and anonymous, and the study was conducted in accordance with national privacy guidelines. Participants gave their informed consent to take part and could have terminated the online survey at any time.
Data were not shared with third parties. The EMS Health study was approved by the ethics committee of HSD Hochschule Döpfer (Mockel et al, 2022).
Questionnaire
For the self-reporting questionnaire, occupation-related items as well as sociodemographic and health-related items were self-described or items and answer options were taken from the questionnaire used in the GEDA 2014/2015 survey (Robert Koch-Institut, 2017; Möckel et al, 2022).
To determine the 12-month prevalence of asthma and allergies, the following question was asked: ‘In the past 12 months, have you had any of the following diseases or conditions?’ and participants could select from a list of diseases, including ‘allergies, such as hay fever, allergic reactions of the eyes or skin, food allergies, or other allergies (not allergic asthma)’, ‘allergies, excluding allergic asthma’ and ‘asthma, including allergic asthma’ (Robert Koch-Institut, 2017).
Occupation-related questions mainly concerned shift work, contractual and actual working hours per week, working environment (rural, metropolitan or urban), prehospital EMS position (physician, nonphysician or trainee) and years spent working in prehospital EMS. Further details on the questionnaire are presented in Möckel et al (2022).
Statistical analysis
First, the 12-month prevalence of asthma (including allergic asthma) and allergies (excluding allergic asthma) were calculated for subgroups based on sociodemographic and occupational characteristics as well as BMI category and smoking status.
To identify associations between these sociodemographic, health and occupational variables and allergy (excluding allergic asthma) as well as asthma (including allergic asthma), univariable analyses were performed using the chi-squared test and logistic regression analysis (Wald statistics), respectively.
All variables with P≤0.1 of being associated with allergies (excluding allergic asthma) or asthma (including allergic asthma) in these univariable analyses were included into multivariable logistic regression for each condition and the adjusted odds ratios (AOR) with corresponding 95% confidence interval (CI) were calculated. Statistical analysis was performed using JASP software and P≤0.05 was considered statistically significant.
Results
Participant characteristics
A total of 2313 prehospital EMS staff (42.59% women; 57.20% men; 0.22% non-binary) with a median age of 25 years (range 18-63 years), was included in the analysis. Overall, 25.47% reported being smokers and the vast majority (75.75%) were single.
More than four out of five (83.36%) participants were working in non-physician prehospital EMS positions, 1.12% were EMS physicians and 15.52% were trainees. On average, practitioners were contracted to work 40.02 (SD 9.17) hours per week, and actually worked 44.79 (SD 11.96) hours. Most (90.62%) participating prehospital EMS staff worked in shifts.
Prevalence of allergies and asthma
The highest 12-month prevalence for allergies (excluding allergic asthma) was found in women (40.61%), trainees (39.55%), those with a BMI<18.5 (36.84%), participants working in rural and urban areas (36.02%) and those with a high school certificate (the Abitur in Germany) (35.66%) ( Table 1 ). For asthma (including allergic asthma) the highest 12-month prevalence was in women (12.28%), physicians (11.54%), participants with a BMI>30 (11.27%), those who had worked for <5 years in EMS (10.90%), and practitioners working in urban areas (10.76%).
| Subgroup | Allergies without allergic asthma | Asthma including allergic asthma | ||
|---|---|---|---|---|
| 12-month prevalence | Chi-squared; P | 12-month prevalence | Chi-squared; P | |
| Gender* | ||||
| Female (n=985) | 40.61% | 49.25; ≤0.001 | 12.28% | 17.34; ≤0.001 |
| Male (n=1323) | 26.76% | 7.18% | ||
| Age groups | ||||
| 18-29 years (n=1508) | 34.48% | 16.10; ≤0.001 | 10.48% | 6.68; 0.036 |
| 30-44 years (n=559) | 32.56% | 7.34% | ||
| 45-64 years (n=246 | 21.55% | 6.91% | ||
| Family status* | ||||
| Single (n=1 752) | 33.90% | 5.82; 0.016 | 9.59% | 0.59; 0.42 |
| Married or registered partnership (n=553 | 28.39% | 8.50% | ||
| Qualifications | ||||
| Elementary school (n=110) | 24.55% | 5.46% | ||
| Secondary school (n=683) | 27.67% | 16.41; ≤0.001 | 9.37% | 3.20; 0.362 |
| Advanced technical college certificate (n=358) | 34.64% | 8.10% | ||
| High school certificate (n=1161) | 35.66% | 9.99% | ||
| Emergency medical services position | ||||
| Non-physician (n=1928) | 31.43% | 9.39% | ||
| Physician (n=26) | 26.92% | 9.47; 0.009 | 11.54% | 0.23; 0.891 |
| Trainee (n=359) | 39.55% | 8.91% | ||
| Shift work | ||||
| No (n=202) | 33.17% | 0.00; 0.963 | 9.90% | 0.10; 0.753 |
| Yes (n=1951) | 33.01% | 9.23% | ||
| Working environment | ||||
| Metropolitan (n=492) | 32.52% | 10.57% | ||
| Urban (n=344) | 31.40% | 5.39; 0.146 | 10.76% | 5.12; 0.163 |
| Rural (n=577) | 30.33% | 7.11% | ||
| Rural and urban (n=744) | 36.02% | 9.41% | ||
| Time working in emergency medical services | ||||
| ≤5 years (n=1073) | 35.04% | 10.90% | ||
| 5 to ≤10 years (n=506) | 33.00% | 8.50% | ||
| 10 to ≤15 years (n=209) | 34.93% | 13.52; 0.009 | 7.66% | 7.35; 0.119 |
| 15 to ≤20 years (n=124) | 29.03% | 5.65% | ||
| ≥20 years (n=244) | 23.36% | 7.38% | ||
| Smoking status | ||||
| No: never smoked (n=1290) | 34.96% | 10.54% | ||
| No: used to smoke (n=430) | 31.63% | 8.28; 0.016 | 8.61% | 5.36; 0.068 |
| Smoker (n=589) | 28.35% | 7.30% | ||
| BMI | ||||
| ≤18.5 (n=38) | 36.84% | 7.90% | ||
| 18.5 to ≤25.0 (n=1005) | 34.73% | 4.53; 0.210 | 9.25% | 2.98; 0.395 |
| 25.0 to ≤30.0 (n=758) | 30.08% | 8.44% | ||
| ≥30 (n=497) | 32.60% | 11.27% | ||
| Variable | Wald statistic; P | Wald statistic; P | ||
| Contractual weekly working hours (n=2078) | 1.34; 0.247 | 0.27; 0.604 | ||
| Actual hours worked per week (n=2051) | 0.91; 0.341 | 0.98; 0.322 | ||
Associations calculated using chi-squared tests or logistic regression analysis
*Non-binary gender (n=5) and widowed participants (n=5) not included because numbers were considered too small
Multivariable analysis showed that variables significantly associated with lower odds of allergies (excluding allergic asthma) in the past 12 months were: being male (AOR 0.57; 95% CI (0.47-0.70); P≤0.001) compared to being female; and being smokers (AOR 0.79; 95% CI (0.62-0.99); P=0.043) compared to participants who have never smoked ( Table 2). Trainees were more likely to have allergies than participants working in non-physician prehospital EMS positions (AOR 1.37; 95% CI (1.061.78); P=0.018).
| Subgroups | Allergies without allergic asthma AOR (95% CI); P* | Asthma including allergic asthma AOR; 95% CI; P* |
|---|---|---|
| Gender** | ||
| Female (n=985) | Reference | Reference |
| Male (n=1323) | 0.57 (0.47-0.70); ≤0.001 | 0.60 (0.45-0.81); p≤0.001 |
| Age group | ||
| 18-29 years (n =1508) | Reference | Reference |
| 30-44 years (n =559) | 1.07 (0.77-1.50); 0.685 | 0.80 (0.55-1.17); 0.247 |
| 45-64 years (n=246 | 0.71 (0.41-1.24); 0.225 | 0.82 (0.48-1.41); 0.464 |
| Family status** | ||
| Single (n=1 752) | Reference | |
| Married or registered partnership (n=553 | 0.99 (0.75-1.30); 0.936 | |
| Qualifications | ||
| Elementary school (n=110) | 1.00 (0.61-1.63); 0.992 | |
| Secondary school (n=683) | Reference | |
| Advanced technical college certificate (n=358) | 1.25 (0.94-1.68); 0.125 | |
| High school certificate (n=1161) | 1.22 (0.96-1.53); 0.099 | |
| Emergency medical services position | ||
| Non-physician (n=1928) | Reference | |
| Physician (n=26) | 0.81 (0.32-2.04); 0.647 | |
| Trainee (n=359) | 1.37 (1.06-1.78); 0.018 | |
| Time working in emergency medical services | ||
| <5 years (n=1073) | Reference | |
| 5 to < 10 years (n=506) | 1.11 (0.87-1.42); 0.399 | |
| 10 to <15 years (n=209) | 1.27 (0.83-1.93); 0.271 | |
| 15 to <20 years (n=124) | 1.09 (0.65-1.84); 0.739 | |
| ≥20 years (n=244) | 1.06 (0.62-1.84); 0.827 | |
| Smoking status | ||
| No: never smoked (n=1290) | Reference | Reference |
| No: used to smoke (n=430) | 1.00 (0.78-1.29); 0.987 | 0.91 (0.62-1.35); 0.651 |
| Smoker (n=589) | 0.79 (0.62-0.99); 0.043 | 0.74 (0.52-1.07); 0.107 |
AOR: adjusted odds ratio; CI: confidence interval
*variables associated with p≤0.1 in the univariable analyses were included into the multivariable logistic regression
**non-binary gender (n=5) and widowed participants (n=5) not analyzed, because number of participates was considered too small
Only gender was significantly associated with asthma (including allergic asthma), with lower odds for men (AOR 0.60; 95% CI (0.45-0.81); P≤0.001) than women (Table 2).
Discussion
The analysis shows a higher 12-month prevalence of allergies or asthma in certain subgroups of the participating prehospital EMS staff from Germany compared to the overall study population, and that these conditions were associated with gender, prehospital EMS position and smoking status.
In comparison to the overall population (32.6% allergies; 9.3% asthma) of the EMS Health Study (Möckel et al, 2022) and therefore in comparison to male participants (Table 1), women had a higher 12-month prevalence of both allergies and asthma. In addition, both conditions were significantly associated with gender in multivariable analysis (Table 2). Within the general German population, women are more likely to be affected by asthma and allergies than men (Heidemann et al, 2021). Furthermore, a study by White et al (2014) indicated that women working in health and social care were affected more frequently by occupational asthma than men (White et al, 2014).
Even though smokers have significantly lower odd for allergies (excluding allergic asthma), this does not indicate that smoking has a protective effect. The authors assume that participants with allergies and asthma are less likely to smoke. In addition to that, the cross-sectional study design does not allow any causal conclusions to be drawn.
EMS trainees had significantly higher odds for allergies, although no association with age was identified. A survey of trainees in general showed that 5% of them abandoned their course because of allergies triggered because of their training (Schuster, 2016).
If the association between allergies and being a trainee found in the present study influences EMS trainee dropout rates, the strength of this cannot be estimated from the data. Further studies should be conducted to investigate which allergies mainly affect prehospital EMS staff and their influence on trainees. This is pertinent since 20% of German trainees do not want to work in prehospital EMS after graduation (Hofmann and Macke, 2020). It is key to eliminate factors that increase German EMS trainee dropout rates.
Finally, it should be mentioned that besides genetic and gender-specific causes, occupational factors such as disinfectants, reduced exposure to germs or changes in eating habits and stress promote asthma and allergies (Lietzen et al, 2011; Schmitz et al, 2017; Steppuhn et al, 2017) and thus could be partly responsible for the prevalence of allergies and asthma in German prehospital EMS staff. In particular, irregular shift work, nonavailability of healthy food and irregular meal times are known to affect prehospital EMS staff (Hegg-Deloye et al, 2014; Gresse et al, 2020).
Limitations
This analysis has several limitations. For example, the conditions were self-reported, and no data were available on which allergies the study participants had and how these influenced their everyday working lives.
There are also no findings on the proportion of allergies and asthma cases requiring medical treatment. Furthermore, it was not possible to deduce the proportion of allergies and asthma cases that were related to work.
In addition, the survey was conducted during the COVID-19 pandemic; the effect of this on study participants cannot be estimated.
Finally, the cross-sectional design of the EMS Health Study does not allow causal conclusions to be drawn. Therefore, the authors recommend conducting longitudinal studies on asthma and allergies in prehospital EMS staff, which could be planned based on the findings of the present study.
Conclusion
This analysis indicates a high prevalence of asthma and allergies in certain subgroups of EMS staff in Germany. Three factors—role, gender and smoking status—were significantly associated with allergies and/or asthma. While trainees had higher odds for allergies, men had lower odds for asthma and allergies and smokers had lower odds for allergies.
Further studies should be conducted to identify which occupational risk factors are causally associated with the occurrence of asthma and allergies in prehospital EMS staff. The identification of risk factors for both conditions is key to avoid a shortage of EMS staff, because allergies can lead to trainees dropping out; many already do not want to work in EMS after graduating.