1. Secondhand smoke exposure and cervical cancer:
Feasibility analysis of NHANES data
Natalie Capps, MNSc, RN1; Chenghui Li, PhD2; Ellyn Matthews, PhD, RN1; Pao Feng Tsai, PhD, RN1
College of Nursing1; College of Pharmacy2, University of Arkansas for Medical Sciences, Little Rock, AR
Within the sample 36.4% reported smoking 100 or more cigarettes in their lifetime and 15.06% of women reported living with a smoker. Of those who live with a smoker, 58.63% live with one smoker, 31.78% live with two smokers, and 9.59% live with three or more smokers. When asked about active smoking, women responded that they do not smoke cigarettes (51.62%), smoke every day (40.88%) or smoke some days (7.5%).
Serum cotinine and urine 4-methylnitrosamino-1-3-pyridyl-1butano (NNAL) are both biological measures of tobacco smoke exposure. Serum cotinine ranged from 0.01 to 920 (M=44.56, SD=110.79) and urine NNAL ranged from 0.0 to 33 (M=0.11, SD=0.77) and was available on 8150 and 7914 subjects respectively of the participants performed vaginal swab HPV testing. Of those 44.4% were HPV positive, 54.9% were HPV negative and 0.6% had inadequate samples. High risk types of HPV for CC are 16, 18, 31, 33, 45, 52, and 58. Within the high risk HPV positive subset the overall the incidence was of high risk HPV was:
BACKGROUND
RESULTS
Variables identified for analysis include self-reported smoking, SHSe,, number of smokers in the household, history of CC, detailed sexual health history, active smoking status, HPV vaccination and housing status. Biological data included: serum cotinine, urine NNAL levels, HPV antibody titer, and vaginal swab HPV testing with DNA analysis for HPV type. Availability of variables of interest is reported below:
Cervical cancer (CC) is among the most preventable health problems worldwide.  Persistent non-treated, high risk human papilloma virus (HPV) is the most causative factor for CC. It is estimated there will be 12,990 new CC cases and 4,120 deaths associated with CC diagnosis in the US in 2016; costing approximately $400 million. High risk HPV strains are causal for CC. They are not, however; sufficient alone for CC. Because of this, it is important to better understand co-factors associated with CC. Co-factors help explain why some women are infected with a high risk HPV strains but do not get CC. Active smoking has been identified as a co-factor for CC. Another co-factor that has been examined, with mixed results, is secondhand smoke exposure (SHSe). These mixed results may be attributable to a wide variety of SHSe measures. The National Health and Nutrition Examination Survey (NHANES) data may provide a solution to varied SHSe measures by reporting on both self-report and biological measures. This data merges the two most common SHSe measures in a large cross-sectional study.
The purpose of this study is to investigate the feasibility of analyzing National Health and Nutrition Examination Survey (NHANES) data to examine the relationship between SHSe and CC. The results of this feasibility study will guide the design and implementation of a larger study examining the relationship between SHSe and CC.
Item
2001-
2002
2003-
2004
2005-
2006
Cotinine: Serum & NNAL urine X
HPV vaginal DHC & blot
HPV vaginal DHC & linear array
HPV antibody titer
Demographic variables
HPV vaccine
History of cervical cancer
Sexual health history
Household smoker
Active smoker
Secondhand smoke exposure
HPV16
HPV18
HPV31
HPV33
HPV45
HPV52
HPV58
Incidence
4.5%
2.1%
1.0%
0.4%
3.3%
2.0%
Women reported a mean of 6.98 lifetime sexual partners and 12.05% reported HPV vaccination. 870 women reported being told they had cancer or a malignancy (9.6%). Of those, 123 reported being diagnosed with cervical cancer in ages ranging from 16 to 80 years.
Based on availability of data, the years were included. Several self-report items, such as education level and sexual health history were only asked of participants ≥ 20 years of age. Because of this, the sample was limited to women ≥ 20 years yielding 9,057 women. Women were between the ages of 20 and 80 (M=49.81, SD=17.96), mostly white (38.7%) and had some college (29.73). Nearly half of the women were married (46.01%) and overwhelmingly US citizens by birth or naturalization (85.98%). Household incomes varied widely with the most commonly reported as $25,000-34,999 (11.81%) and > $100,000 (12.7%). Racial/ethnic and education results are displayed on figure 1 and 2 respectively.
CONCLUSIONS
The data is available to examine the relationship between SHSe and CC. A power analysis should be performed to identify if the available data is robust enough for further analysis. Reported levels of CC history are relatively low but cases may be weighted for further statistical analysis. SHSe can be measured through the surrogate of living with a smoker. There are several variables with missing data, however; none fell outside of the 10% standard. Some women elected not to participate in the vaginal HPV swab testing, cotinine and/or NNAL levels. The analysis of HPV type included here does not account for the incidence of women who were positive for more than one HPV type infection. Further studies should analyze the incidence of multiple high-risk HPV type infections. .
METHODS
This secondary data analysis investigated the feasibility of utilizing the cross-sectional NHANES data for analysis of SHSe and CC. The NHANES data were reviewed for variables that are pertinent to SHSe and CC risk. Data is released in 2 year increments on a rolling basis. Released data was screened for variables of interest. Questions and biological reports were individually analyzed for applicability to the question of interest. Following identification, variables were analyzed for availability by years. NHANES data is continuous, but has variation in reporting depending on year. After selecting the best years for analysis based on variables of interest, data was merged using SPSS IBM Statistics 23. The data was then limited to include only women ≥20 years old in the reporting years Descriptive statistics were used to describe the data available in the variables of interest.
Figure 1
Figure 2
DISCUSSION
The NHANES survey provides a good dataset with which to examine many possible medical issues. It is limited by retrospective and secondary analysis, however; reviewing this large cross-sectional survey may help guide the direction of prospective studies