Firefighter occupational factors and the risk of preterm birth: results from a survey of women firefighters in the USA.

OBJECTIVES: Previous research has suggested that women firefighters may have a greater risk of adverse reproductive outcomes compared with non-firefighting women. In this study, we investigated the association between firefighter occupational factors and risk of preterm birth. METHODS: This cross-sectional analysis of US firefighters surveyed in 2017 compared preterm birth among firefighters to non-firefighters using age-at-pregnancy-standardised prevalence ratios. Generalised estimating equations estimated relative risks and 95% CIs between firefighter occupational factors (career or volunteer, wildland status, shift schedule, fire responses, work restriction) and preterm birth risk. We adjusted for age-at-pregnancy, education, gravidity, BMI, and smoking and considered effect modification by age-at-pregnancy and career versus volunteer status. RESULTS: Among 934 women who reported 1356 live births, 12% were preterm (n=161). Preterm birth prevalence among firefighters was 1.41 times greater than non-firefighters (95% CI 1.18 to 1.68). Among wildland and combination wildland/structural firefighters, volunteers had 2.82 times the risk of preterm birth (95% CI 1.19 to 6.67) compared with career firefighters. Firefighters who started restricting their work in the 2nd trimester had a nonsignificant 0.67 times lower risk of preterm birth than those who started in the 3rd trimester or did not restrict work at all (95% CI 0.43 to 1.03). CONCLUSIONS: Firefighters may have greater risk of preterm birth than non-firefighters, which could be influenced by roles in the fire service and work restrictions taken.

Evaluating the Strength of Association of Human Papillomavirus Infection With Penile Carcinoma: A Meta-Analysis.

BACKGROUND: Human papillomavirus (HPV) is a common sexually transmitted infection that is strongly associated with cervical cancer. A link to penile cancers has been suggested by case series. We sought to assess the strength of the association between HPV infection and penile cancer by meta-analysis. METHODS: A literature search to identify population-based studies evaluating the risk of HPV infection with penile cancer was conducted via PubMed and Google Scholar databases through December 2020. Studies were included in the pooled analyses if they presented relative risk (RR) estimates comparing penile cancer cases with noncases by HPV exposure status. They were stratified by (1) type of HPV, (2) test used to determine past HPV infection, and (3) the penile cancer type. Pooled analyses were conducted for stratum with at least 2 independent studies using fixed-effects and random-effects models. RESULTS: Fourteen articles representing 9 study populations fit the inclusion criteria and were included in the pooled analysis. Based on these studies, the pooled RRs are 2.9 (95% confidence interval [CI], 1.7-5.0; n = 4 studies) for invasive penile cancer and seropositivity to HPV16 L1, 4.5 (95% CI, 1.3-15.5; n = 2) for seropositivity to HPV18, and 8.7 for anogenital warts (95% CI, 5.1-14.8; n = 5). For the 3 studies reporting invasive and in situ penile cancer, the risk was 7.6 for anogenital warts. CONCLUSIONS: The pooled RRs indicate up to a 4.5-fold increased risk between seropositivity for HPV infection and invasive penile cancer. This is much lower than associations seen between HPV and cervical cancer.

Occupational factors and miscarriages in the US fire service: a cross-sectional analysis of women firefighters.

BACKGROUND: Evidence from previous studies suggests that women firefighters have greater risk of some adverse reproductive outcomes. The purpose of this study was to investigate whether women firefighters had greater risk of miscarriage compared to non-firefighters and whether there were occupational factors associated with risk of miscarriage among firefighters. METHODS: We studied pregnancies in the United States fire service using data from the Health and Wellness of Women Firefighters Study (n = 3181). We compared the prevalence of miscarriage among firefighters to published rates among non-firefighters using age-standardized prevalence ratios. We used generalized estimating equations to estimate relative risks (RRs) and 95% confidence intervals (CIs) between occupational factors (employment (career/volunteer), wildland firefighter status (wildland or wildland-urban-interface/structural), shift schedule, fire/rescue calls at pregnancy start) and risk of miscarriage, adjusted for age at pregnancy, education, gravidity, BMI, and smoking. We evaluated if associations varied by age at pregnancy or employment. RESULTS: Among 1074 firefighters and 1864 total pregnancies, 404 pregnancies resulted in miscarriages (22%). Among most recent pregnancies, 138 resulted in miscarriage (13%). Compared to a study of US nurses, firefighters had 2.33 times greater age-standardized prevalence of miscarriage (95% CI 1.96-2.75). Overall, we observed that volunteer firefighters had an increased risk of miscarriage which varied by wildland status (interaction p-value< 0.01). Among structural firefighters, volunteer firefighters had 1.42 times the risk of miscarriage (95% CI 1.11-1.80) compared to career firefighters. Among wildland/wildland-urban-interface firefighters, volunteer firefighters had 2.53 times the risk of miscarriage (95% CI 1.35-4.78) compared to career firefighters. CONCLUSIONS: Age-standardized miscarriage prevalence among firefighters may be greater than non-firefighters and there may be variation in risk of miscarriage by fire service role. Further research is needed to clarify these associations to inform policy and decision-making.

Does weather trigger urologic chronic pelvic pain syndrome flares? A case-crossover analysis in the multidisciplinary approach to the study of the chronic pelvic pain research network.

BACKGROUND: To investigate whether meteorological factors (temperature, barometric pressure, relative humidity, ultraviolet index [UVI], and seasons) trigger flares in male and female urologic chronic pelvic pain patients. METHODS: We assessed flare status every 2 weeks in our case-crossover study of flare triggers in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain 1-year longitudinal study. Flare symptoms, flare start date, and exposures in the 3 days preceding a flare or the date of questionnaire completion were assessed for the first three flares and at three randomly selected nonflare times. We linked these data to daily temperature, barometric pressure, relative humidity, and UVI values by participants' first 3 zip code digits. Values in the 3 days before and the day of a flare, as well as changes in these values, were compared to nonflare values by conditional logistic regression. Differences in flare rates by astronomical and growing seasons were investigated by Poisson regression in the full study population. RESULTS: A total of 574 flare and 792 nonflare assessments (290 participants) were included in the case-crossover analysis, and 966 flare and 5389 nonflare (409 participants) were included in the full study analysis. Overall, no statistically significant associations were observed for daily weather, no patterns of associations were observed for weather changes, and no differences in flare rates were observed by season. CONCLUSIONS: We found minimal evidence to suggest that weather triggers flares, although we cannot rule out the possibility that a small subset of patients is susceptible.

Emerging Evidence for Infectious Causes of Cancer in the United States.

Worldwide, infectious agents currently contribute to an estimated 15% of new cancer cases. Most of these (92%, or 2 million new cancer cases) are attributable to 4 infectious agents: Helicobacter pylori, human papillomavirus, and hepatitis B and C viruses. A better understanding of how infectious agents relate to the US cancer burden may assist new diagnostic and treatment efforts. We review US-specific crude mortality rates from infection-associated cancers and describe temporal and spatial trends since 1999. We review the US-specific evidence for infection-cancer associations by reporting available estimates for attributable fractions for the infection-cancer associations. Death due to cancers with established infectious associations varies geographically, but estimates for the US attributable fraction are limited to a few observational studies. To describe the burden of infection-associated cancer in the United States, additional observational studies are necessary to estimate the prevalence of infection nationally and within subpopulations. As infectious associations emerge to explain cancer etiologies, new opportunities and challenges to reducing the burden arise. Improved estimates for the United States would help target interventions to higher-risk subpopulations.

Sun sensitivity and sun protective behaviors during sun exposure among indoor office workers in the American Midwest.

BACKGROUND/PURPOSE: Sun sensitivity, a confounder between sun exposure and sun protection, is often overlooked. We examined how sun exposure and sun protection behaviors among indoor workers varied by sun sensitivity. METHODS: Sun exposure and sun protection diaries over a 45-day period from Midwestern United States indoor workers were examined. We categorized sun sensitivity (fair and non-fair complexion) using tanning inability and sunburn tendency. Total exposure (sunrise to sunset) and peak exposure (10 am and 4 pm) lasting at least 60 minutes were examined. Percentages of time using sun protection were reported. We determined associations between fair complexion, mean sun exposure, and mean sun protection times with logistic regression. RESULTS: Fair individuals spent less time in the sun than non-fair individuals, but a greater proportion of time using sun protection behaviors, including sunscreen with SPF 30+ (odds ratio (OR) = 1.36; 95% confidence interval (95% CI) = 0.98, 1.87)), or wearing long-sleeved shirts (OR = 2.89; 95% CI = 1.24, 6.73). CONCLUSION: Fair individuals spent less time in the sun and practiced more sun protective behaviors than non-fair individuals. This complex association between sun sensitivity, sun protection and sun exposure has not consistently been addressed in studies of skin cancer.

Interrater and Test-Retest Reliability of the Beery Visual-Motor Integration in Schoolchildren.

PURPOSE: To assess interrater and test-retest reliability of the 6th Edition Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) and test-retest reliability of the VMI Visual Perception Supplemental Test (VMIp) in school-age children. METHODS: Subjects were 163 Native American third- to eighth-grade students with no significant refractive error (astigmatism <1.00 D, myopia <0.75 D, hyperopia <2.50 D, anisometropia <1.50 D) or ocular abnormalities. The VMI and VMIp were administered twice, on separate days. All VMI tests were scored by two trained scorers, and a subset of 50 tests was also scored by an experienced scorer. Scorers strictly applied objective scoring criteria. Analyses included interrater and test-retest assessments of bias, 95% limits of agreement, and intraclass correlation analysis. RESULTS: Trained scorers had no significant scoring bias compared with the experienced scorer. One of the two trained scorers tended to provide higher scores than the other (mean difference in standardized scores = 1.54). Interrater correlations were strong (0.75 to 0.88). VMI and VMIp test-retest comparisons indicated no significant bias (subjects did not tend to score better on retest). Test-retest correlations were moderate (0.54 to 0.58). The 95% limits of agreement for the VMI were -24.14 to 24.67 (scorer 1) and -26.06 to 26.58 (scorer 2), and the 95% limits of agreement for the VMIp were -27.11 to 27.34. CONCLUSIONS: The 95% limit of agreement for test-retest differences will be useful for determining if the VMI and VMIp have sufficient sensitivity for detecting change with treatment in both clinical and research settings. Further research on test-retest reliability reporting 95% limits of agreement for children across different age ranges is recommended, particularly if the test is to be used to detect changes due to intervention or treatment.

Does artificial UV use prior to spring break protect students from sunburns during spring break?

BACKGROUND: Dark-skinned individuals are less likely than light-skinned individuals to become sunburned or develop skin cancer. Some have extrapolated this relationship and surmised that developing and maintaining a tan will reduce the risk of sunburns and melanoma. In order to examine whether this strategy indeed protects against sunburns, we surveyed college students about both their tanning habits prior to spring break and their spring break activities. METHODS: Sorority and fraternity students were recruited after spring break. Analyses examined associations between potential risk factors and the development of one or more sunburns during spring break. RESULTS: As expected, the risk of obtaining a sunburn increased with: time spent in the sun during spring break; light complexion, as assessed by various sun-sensitivity factors; and lack of sunscreen use. We also found that tanning using an artificial UV source during the 10 weeks prior to spring break was not associated with reduced risk of sunburns during spring-break, but rather with a marginal increase in this risk. CONCLUSIONS: These data provide evidence that maintaining a tan may not provide protection from sunburns. Public health messages need to address this misconception, stating clearly that a tan does not protect against or reduce the chances of developing a sunburn.

Comparison of Prognostic Factors for Merkel Cell Carcinoma, Mucosal Melanoma and Cutaneous Malignant Melanoma: Insights into Their Etiologies.

Little is known about the epidemiology of Merkel cell carcinoma (MCC) and mucosal melanoma (MM). Using the United States (US) National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program data, we compared MCC and MM with cutaneous malignant melanoma (CMM) with respect to incidence rates and prognostic factors to better understand disease etiologies. We describe the proportional incidences of the three cancers along with their survival rates based on 20 years of national data. The incidence rates in 2000-2019 were 203.7 per 1,000,000 people for CMM, 5.9 per 1,000,000 people for MCC and 0.1 per 1,000,000 people for MM. The rates of these cancers increased over time, with the rate of MM tripling between 2000-2009 and 2010-2019. The incidences of these cancers increased with age and rates were highest among non-Hispanic Whites. Fewer MCCs and MMS were diagnosed at the local stage compared with CMM. The cases in the 22 SEER registries in California were not proportional to the 2020 population census but instead were higher than expected for CMM and MCC and lower than expected for MM. Conversely, MM rates were higher than expected in Texas and New York. These analyses highlight similarities in the incidence rates of CMM and MCC-and differences between them and MM rates-by state. Understanding more about MCC and MM is important because of their higher potential for late diagnosis and metastasis, which lead to poor survival.

Validity of a Self-Assessment Skin Tone Palette Compared to a Colorimeter for Characterizing Skin Color for Skin Cancer Research.

Our goal is to determine whether our objective 9-point Self-Assessment Skin Tone Palette (SASTP) is correlated with a colorimeter's assessment of a melanin index, so that Hispanic and Black people can be included in skin cancer research where scales were developed for White populations. Subjects were asked to self-identify their skin tones using the SASTP. This study assessed the criterion validity of the SASTP by measuring a range of skin colors compared to a melanin index reported from a colorimeter for the upper-inner arm (non-sun-exposed skin color), and the outer forearm (sun-exposed). Among 188 non-artificial tanners, 50% were White, 30% were Hispanic or White-Hispanic, and 20% were other racial categories. Meanwhile, 70% were female (30% male) and 81% were age 18-29 (19% age 30+). The mean melanin of the upper-inner arm decreased with lighter skin color and stronger tendency to burn. The SASTP in comparison to melanin index values was correlated for both the upper-inner arm (r = 0.81, p < 0.001) and the outer forearm (r = 0.77, p < 0.001). The SASTP provides a 9-point scale that can be considered as an alternative, less expensive method that is comparable to the objective colorimeter melanin index, which may be useful in studies on skin cancer among White, non-White, and Hispanic peoples.

A meta-analysis of sunburn and basal cell carcinoma risk.

Basal cell carcinoma (BCC) is the most common cancer in the United States. Sunburn is a modifiable risk factor for BCC. The objective of this project was to synthesize research on BCC and sunburn to quantify the impact and severity of sunburn at different life stages on BCC risk in the general population. A systematic literature search of four electronic databases was conducted and data were extracted by two independent reviewers using standardized forms. Data from 38 studies were pooled using both dichotomous and dose-response meta-analytic methods. BCC risk increased with ever experiencing a sunburn in childhood (OR=1.43, 95% CI: 1.19, 1.72) and with ever experiencing a sunburn in life (OR= 1.40, 95% CI: 1.02, 1.45). Every five sunburns experienced per decade in childhood increased BCC risk by 1.86 (95% CI: 1.73, 2.00) times. Every five sunburns experienced per decade in adulthood increased BCC risk by 2.12 (95% CI: 1.75, 2.57) times and every five sunburns per decade of life increased BCC risk by 1.91 (95% CI: 1.42, 2.58) times. The data on sunburn exposure and BCC show that an increase in number of sunburns at any age increased the risk of BCC. This may inform future prevention efforts.

Cumulative Sun Exposure and Melanoma in a Population-Based Case-Control Study: Does Sun Sensitivity Matter?

Cutaneous melanoma (CM) has consistently been associated with intermittent sun exposure, while the association with chronic sun exposure is debated. The goal of this research was to examine the complex relationship between CM, sun sensitivity and sun exposure based on theoretical concepts of how these factors may be associated. Detailed sun exposure histories across life periods and various measures of sun sensitivity were collected in a population-based case-control study of melanoma in Iowa, USA. Participants were asked about their hours of sun exposure per day between March and October each year over periods or decades of life to estimate cumulative lifetime hours of sun exposure. Increased odds ratios (ORs) for CM were seen for most standard measures of sun sensitivity except for the tendency to sunburn. Minimal associations were seen with total hours of sun exposure early in life. However, an interaction was seen between fair skin color and lifetime hours of sun exposure, where the strongest associations with CM were seen among medium-skinned and dark-skinned participants. This suggests that cumulative sun exposure at high levels may increase CM among non-sun-sensitive individuals typically at lower risk of CM. Such a finding has implications for the prevention effort for melanoma regarding time in the sun among darker-skinned individuals.

Ambient UVR and Environmental Arsenic Exposure in Relation to Cutaneous Melanoma in Iowa.

Intermittent sun exposure is the major environmental risk factor for cutaneous melanoma (CM). Cumulative sun exposure and other environmental agents, such as environmental arsenic exposure, have not shown consistent associations. Ambient ultraviolet radiation (UVR) was used to measure individual total sun exposure as this is thought to be less prone to misclassification and recall bias. Data were analyzed from 1096 CM cases and 1033 controls in the Iowa Study of Skin Cancer and Its Causes, a population-based, case-control study. Self-reported residential histories were linked to satellite-derived ambient UVR, spatially derived environmental soil arsenic concentration, and drinking water arsenic concentrations. In men and women, ambient UVR during childhood and adolescence was not associated with CM but was positively associated during adulthood. Lifetime ambient UVR was positively associated with CM in men (OR for highest vs. lowest quartile: 6.09, 95% confidence interval (CI) 2.21-16.8), but this association was not as strong among women (OR for highest vs. lowest quartile: 2.15, 95% CI 0.84-5.54). No association was detected for environmental soil or drinking water arsenic concentrations and CM. Our findings suggest that lifetime and adulthood sun exposures may be important risk factors for CM.

Reduction in Standard Cancer Screening in 2020 throughout the U.S.

Cancer screening is an important way to reduce the burden of cancer. The COVID-19 pandemic created delays in screening with the potential to increase cancer disparities in the United States (U.S.). Data from the 2014-2020 Behavioral Risk Factor Surveillance System (BRFSS) survey were analyzed to estimate the percentages of adults who reported cancer screening in the last 12 months consistent with the U.S. Preventive Services Task Force (USPSTF) recommendation for cervical (ages 21-65), breast (ages 50-74), and colorectal cancer (ages 50-75) prior to the pandemic. Cancer screening percentages for 2020 (April-December excluding January-March) were compared to screening percentages for 2014-2019 to begin to look at the impact of the COVID-19 pandemic. Screening percentages for 2020 were decreased from those for 2014-2019 including several underserved racial groups. Decreases in mammography and colonoscopy or sigmoidoscopy were higher among American Indian/Alaskan Natives, Hispanics, and multiracial participants, but decreases in pap test were also highest among Hispanics, Whites, Asians, and African-Americans/Blacks. Decreases in mammograms among women ages 40-49 were also seen. As the 2020 comparison is conservative, the 2021 decreases in cancer screening are expected to be much greater and are likely to increase cancer disparities substantially.

Objective Assessment of Spectacle Wear in Infants and Toddlers Using a Wearable Sensor.

Purpose: To assess the feasibility of using a thermal microsensor to monitor spectacle wear in infants and toddlers, to determine the inter-method reliability of two methods of estimating spectacle wear from sensor data, and to validate sensor estimates of wear. Methods: Fourteen children, 3 to <48 months of age, and one adult were provided pediatric spectacles containing their spectacle prescription. A thermal microsensor attached to the spectacle headband recorded date, time, and ambient temperature every 15 minutes for 14 days. Parents were asked for daily spectacle wear reports, and the adult recorded wear using a smartphone app. Sensor data were dichotomized (wear/non-wear) using two methods: temperature threshold (TT) and human judgment (HJ). Kappa statistics assessed inter-method reliability (child data) and accuracy (adult data). Results: Data from two child participants were excluded (one because of corrupted sensor data and the other because of no parent log data). Sensor data were collected more reliably than parent wear reports. The TT and HJ analysis of child data yielded similar reliability. Adult sensor data scored using the HJ method provided more valid estimates of wear than the TT method (κ = 0.94 vs. 0.78). Conclusions: We have demonstrated that it is feasible to deduce periods of spectacle wear using a thermal data logger and that the sensor is tolerated by children. Translational Relevance: Results indicate that it is feasible to use a thermal microsensor to measure spectacle wear for use in clinical monitoring or for research on spectacle treatment in children under 4 years of age.

Age and Cohort Trends of Malignant Melanoma in the United States.

The incidence of malignant melanoma in the United States is increasing, possibly due to changes in ultraviolet radiation (UVR) exposure due to lifestyle or increased awareness and diagnosis of melanoma. To determine if more recent birth cohorts experience higher rates of melanoma as they age, we examined age and birth cohort trends in the United States stratified by anatomic site and cancer type (in situ vs. malignant) of the melanoma diagnosed from 1975-2017. Poisson regression of cutaneous melanoma cases per population for 1975-2017 from the Surveillance, Epidemiology, and End Results (SEER) cancer registries was used to estimate age adjusted incidence for five-year birth cohorts restricted to Whites, ages 15-84. The rate of melanoma incidence across birth cohorts varies by anatomic site and sex. Melanomas at all anatomic sites continue to increase, except for head and neck melanomas in men. Much of the increase in malignant melanoma is driven by cases of thin (<1.5 mm) lesions. While increased skin exams may contribute to the increased incidence of in situ and thin melanoma observed across birth cohorts, the shifts in anatomic site of highest melanoma incidence across birth cohorts suggest changes in UVR exposure may also play a role.

Racial differences in prostate cancer risk remain among US servicemen with equal access to care.

BACKGROUND: Prostate cancer is the most common cancer among US men, however, the etiology remains unclear. Yet, one consistency is that black non-Hispanic men are at increased risk for prostate cancer compared to white, non-Hispanic men. The goal of this study was to assess relations between demographic and other potential prostate cancer risk factors in the context of the US military healthcare system, which provides equal access to all US servicemen. METHODS: Military healthcare and demographic data were used to describe risk factors for prostate cancer in the US military from September 1993 to September 2003. Cox's proportional hazards regression was employed to model the time to prostate cancer hospitalization. RESULTS: Four hundred eight first prostate cancer hospitalizations were identified among 2,761,559 servicemen. The adjusted rate per 100,000 persons rose from 1.41 to 3.62 for white non-Hispanic men and 1.43 to 6.08 for black non-Hispanic men by the end of the study. The increasing incidence over time for combined race/ethnic groups was similar to trends reported in the Surveillance, Epidemiology, and End Results Program for the US civilian population. No association was observed between occupation and prostate cancer hospitalization. However, black non-Hispanic men were at increased risk compared with white non-Hispanic men (hazard ratio = 2.72, 95% confidence interval: 2.12, 3.49). CONCLUSIONS: No association was observed between occupation and prostate cancer hospitalization. In this relatively young cohort, black non-Hispanic race/ethnicity was found to be predictive of prostate cancer, and this association existed regardless of access to care and socioeconomic status.

Factors related to physicians' willingness to vaccinate girls against HPV: the importance of subjective norms and perceived behavioral control.

This study assessed factors related to physicians' intentions to vaccinate patients against human papillomavirus. A random sample of physicians was surveyed. The survey questions focused on the constructs of the Theory of Planned Behavior. Structural equation modeling was used to estimate the relationship of theoretical constructs to intention to vaccinate. Of the 207 physicians who responded, intentions to vaccinate were very high (86.5%). On a scale of 1 to 7 (strongly disagree to strongly agree) physicians had positive attitudes toward the vaccine. Physicians reported the vaccine was a good idea (M = 6.65, SD = 0.79), beneficial (M = 6.64, SD = 0.76), and protected against cervical cancer (M = 6.63, SD = 0.77). Intention to vaccinate was driven by subjective norms (provided by guidelines or standards of practice by important professional and general referent groups) (beta = 1.00, p < 0.05) and perceived behavioral control (beta = 0.39, p < 0.05). These findings indicate that public health efforts to encourage physicians to adopt the human papillomavirus vaccine should focus on subjective norms, such as those provided by professional organizations.

Using the theory of planned behavior to predict mothers' intentions to vaccinate their daughters against HPV.

This study assessed mothers' intentions to vaccinate their daughters against human papillomavirus (HPV) using the theory of planned behavior (TPB). Experience with sexually transmitted infections (STIs), beliefs about the vaccine encouraging sexual activity, and perception of daughters' risk for HPV were also examined for a relationship with intention. A random sample of mothers in a rural, Midwestern state were mailed a survey with questions pertaining to the intention to vaccinate. Attitudes were the strongest predictor of mothers' intentions to vaccinate, but intentions were not high. Subjective norms also influence intention. Mothers' risk perceptions, experience with STIs, and beliefs about the vaccine encouraging sexual activity were not related to intention. Mothers' perceptions of the daughters' risks for HPV were surprisingly low. This research provides a foundation for designing interventions to increase HPV vaccination rates. Further research should explore ways to influence mothers' attitudes and to uncover the referent groups mothers refer to for vaccination behavior.