Factors determining early adherence to a lung cancer screening protocol

Our plain-English summary of Factors determining early adherence to a lung cancer screening protocol, by U. Montes, L.M. Seijo, A. Campo, et al (The European Respiratory Journal, 2007).

The study

• Authors: U. Montes, L.M. Seijo, A. Campo, A.B. Alcaide, G. Bastarrika, J.J. Zulueta
• Journal: The European Respiratory Journal
• Published: 2007;30(3):532-7
• Cited by: 50 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Lung cancer screening using computed tomography (CT) is effective in detecting early stage disease. However, concerns regarding adherence have been raised. The current authors conducted a retrospective observational study of 641 asymptomatic smokers enrolled in a lung cancer screening programme between 2000 and 2003. Adherent subjects were compared with nonadherent subjects with regard to lung function, sex, age, motivation for enrollment, smoking status, distance to the referral centre, family history of lung cancer, asbestos exposure, education, the presence and type of nodule(s) seen on initial CT, and exposure to a nursing intervention designed to improve adherence. Overall, early adherence to the study protocol was 65%. Multivariate analysis confirmed the importance of sex, proximity to the referral centre, the presence of noncalcified nodules, and the nursing intervention as factors conditioning adherence to the study protocol. Patients encouraged to participate in the study were more adherent, as were former smokers. Sex interactions were observed in multivariate analysis. The nursing intervention was significant for females, while abnormal lung function improved male adherence. Adherence to lung cancer screening is particularly good among females and subjects living near the referral centre. The present study suggests the need to develop new strategies, especially those targeting males and subjects with low risk perception, in order to improve adherence.

In plain English

This retrospective study examined what influenced adherence to CT lung cancer screening. It covered 641 at-risk smokers and former smokers enrolled in 2000 to 2003 at the University of Navarra, Spain, part of I-ELCAP. People counted as early adherent if they returned for a second scan within 18 months. Overall early adherence was 65%. It was 80% among people living within 200 km of the centre versus 58% among those farther away, and 75% among women versus 57% among men. Also linked to better adherence were a noncalcified lung nodule on the first scan, a nursing reminder programme begun in 2003, enrolling on family or medical advice, and being a former smoker. The nursing programme did not significantly help men. The authors reported that asbestos exposure, smoking pack-years, age, education and family history of lung cancer had no effect on adherence, although their separate analysis of men found age associated with adherence. The authors concluded that men and people with low risk perception were particularly challenging and that strategies to improve adherence may need to be sex-specific.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: retrospective study of participants in a lung cancer screening programme using low-dose CT
• Who was studied: 641 at-risk subjects (smokers or former smokers aged 40 or over with at least 10 pack-years) in the University of Navarra lung cancer screening programme, Pamplona, Spain, a member of I-ELCAP, enrolled 2000 to 2003
• Exposure: Not an asbestos exposure study. The authors compared adherent and nonadherent subjects on many factors, of which asbestos exposure was one. No fiber type and no method of measuring asbestos exposure are described. The other factors were COPD/lung function, sex, age, motivation for enrolment, smoking status, education, family history of lung cancer, distance to the centre, nodules on the first CT, risk perception and a nursing intervention.
• Main results:
  • Overall early adherence (second CT scan within 18 months) at the authors' centre was 65%.
  • 80% of subjects living within 200 km of the referral centre returned for a repeat scan within 18 months, compared with 58% of those living farther away.
  • Distance to the referral centre remained significant in multivariate analysis: OR 2.55, 95% CI 1.65 to 3.95.
  • Adherence was 75% among female participants and 57% among males. In multivariate analysis, sex had OR 2.07, 95% CI 1.41 to 3.04.
  • 74% of subjects with at least one noncalcified pulmonary nodule returned for a second scan, compared with 61% of those without (p less than 0.01). In multivariate analysis, OR 2.75, 95% CI 1.77 to 4.29, for males and females.
  • The nursing intervention improved adherence overall (multivariate OR 3.12, 95% CI 2.10 to 4.84), but did not significantly improve adherence among males.
  • Among females, the nursing intervention was associated with adherence: OR 10.01, 95% CI 4.90 to 20.45.
  • Subjects encouraged to participate by their family or physician were more adherent (multivariate OR 1.54, 95% CI 1.03 to 2.30).
  • Former smokers were more adherent than current smokers: OR 2.00, 95% CI 1.21 to 3.28.
  • Among males, abnormal lung function was associated with adherence: OR 2.09, 95% CI 1.19 to 3.67.
  • Among males, age was associated with adherence in the sex-specific multivariate analysis: OR 1.07, 95% CI 1.03 to 1.10.
  • Asbestos exposure, cumulative pack-years, age, education level and family history of lung cancer had no effect on adherence, according to the authors. Age is nonetheless reported as associated with adherence among males.
  • Among 52 nonadherent subjects contacted by telephone, the self-reported reasons were oversight or lack of time (44%), distance to the referral centre (21%), a 'benign initial CT' (14%) and cost (12%).
• The authors' conclusion: The authors concluded that males and subjects with low risk perception are particularly challenging, that cost and distance pose additional challenges, and that strategies such as nursing intervention have succeeded but may need to be sex-specific.
• Limitations the authors state:
  • Retrospective design. The data came from a questionnaire that was not designed to study adherence.
  • Changes in attitudes caused by taking part, such as anxiety over abnormal scans, could not be measured.
  • Household income was not asked, although cost was a self-reported reason for nonadherence.
  • The true impact of the nursing intervention is uncertain because the groups were compared at different time periods (before and after 2003).
  • The attempt to contact a representative group of nonadherent subjects has obvious pitfalls.
  • The centre tends to attract higher-income private patients, so the impact of cost on nonadherence may have been underestimated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

Medical terms in this study, explained in our Lexicon: Low-Dose CT Screening, Lung Cancer, Asbestos Exposure, Multivariate Analysis.

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