Systematic Literature Reviews and Outdoor Smoking in Public Places

Introduction to Systematic Literature Searches and Reviews

Probing, seriously investigating, and synthesizing the literature are vital skills for researchers. There is a massive amount of text and other material that is easily accessible, and it can be genuinely difficult to identify where to begin. It is therefore imperative that one is methodical — organized and precise — in one's approach while searching through available information. It is important to understand the search plan: what to include and what to exclude. For example, one might consider only studies that feature randomized controlled trials, or select only those studies published within the last five years because that is where changes in health policy have been most prominent. The databases searched and the keywords used should always be recorded.

In a systematic literature review, evidence from prior studies is located, examined, and synthesized using a rigorous and logical scientific approach. Once this process is complete, a systematic search becomes a systematic review. This involves reading all identified references thoroughly — while time may not permit reading every source in full, summaries can be read for most, with complete articles consulted for the most important ones. The process of what was included and what was excluded should be documented as part of the study.

The primary purpose of the systematic review is to produce a comprehensive and impartial assessment of the available evidence. Once the research has been located and assessed against acceptance and rejection criteria — such as requiring up-to-date journals and robust designs like randomized controlled trials (RCTs) — the results are typically organized into thematic topics. The topics that emerge from the research and all references within each topic must be documented. Part of the search process may also involve consultations with subject-matter experts. It is essential to document how sources were retrieved at every stage of the search process. After the initial search, a large number of articles may be returned, requiring further filtering — for instance, limiting results to English-language articles with strong research designs, or restricting the search to psychological rather than sociological databases (see Saks, 2007, under Systematic Review).

Steps for Conducting a Systematic Search

By following these steps, a researcher is conducting a methodical, systematic search. The example that follows illustrates this process in the context of a literature review focused on patient issues.

Patient Issues and Non-Peer-Reviewed Sources in Literature Reviews

Incorporating the patient's perspective from the very first stage of the process is essential if the review is to have a meaningful effect on the definition of final parameters. One of the instruments used to achieve this precise focus on patient issues involves documenting findings prior to the initial meeting of a guideline development group. The scope of this type of search is not restricted to any particular study design; it is structured to take into account both quantitative and qualitative evidence. As part of a literature review, it is conducted in a similar fashion to other searches, drawing on the same range of databases and sources. It differs in that it also covers nursing and psychological literature, even where there is no specific connection to the medical literature used in subsequent searches. The results of this type of search are then filtered to identify publications relevant to the guideline topic. Using a standard checklist, the methodology of each paper is evaluated wherever feasible. The evaluation and search process may be classified into groups that direct attention to the primary concerns of the patients involved. These insights are then used by the guideline development group to help articulate the essential questions related to those patients.

Non-peer-reviewed sources are sometimes referred to as grey literature. Such materials may not have undergone peer review, but they can still be of high value and should be taken into account. This category includes reports and monographs typically published by government agencies, welfare and community organizations, and universities. Grey literature is commonly available online. Useful sources include the United States Centers for Disease Control and Prevention and comparable government health departments in other countries.

Note: The majority of references cited in academic work should come from peer-reviewed sources, including research and scientific journals and articles.

Smoking in Urban Outdoor Public Places: Introduction and Epidemiology

The increasing number of restrictions on indoor smoking has contributed to a growing trend of smoking outside the home. This has created an emerging public health and social concern in urban environments. Outdoor smokers affect people in their immediate surroundings and expose them to secondhand smoke. According to research, approximately 53% of Canadian adults are exposed to secondhand smoke when entering a building (Health Canada, 2008).

In outdoor environments, smoking creates public health concerns because there is no established safe level of exposure (US Department of Health and Human Services, 2006). Outdoor smoking and the associated exposure have a considerable impact on bystanders, comparable in some respects to indoor smoking exposure (Repace, 2005; California Air Resources Board, 2005; Klepeis et al., 2007; Hall et al., 2009). A further report suggests that tobacco smoke near building entrances is a major concern, as its harmful effects may exceed those of other outdoor sources (Kaufman et al., 2009; Kennedy et al., 2009).

Secondhand smoke is considered a major contributing factor to increased rates of respiratory disease, lung and nasal cancer, and breathing difficulties. It can also cause the following medical concerns for both smokers and non-smokers:

Short-term smoke exposure can cause problems for individuals with sensitive cardiovascular systems (US Department of Health and Human Services, 2006; Barnoya and Glantz, 2005; Sargent et al., 2004; Pechacek and Babb, 2004) and may also lead to respiratory irritation, eye irritation, and asthma (US Department of Health and Human Services, 2006). A recent study found that even brief exposures of approximately 30 minutes can cause vascular damage and injury (Heiss et al., 2008). In addition, smoking near building entrances increases fire risk, contributes to toxic litter, and creates a negative impression of the building for visitors (Nagle et al., 1996; Parry et al., 2000; Alesci et al., 2003). These concerns have collectively contributed to an increase in jurisdictional measures implementing smoking restrictions in public places (Kaufman et al., 2010).

Conclusion

A number of practical and policy-related challenges exist in banning smoking from public places. While the health consequences of this habit are widely acknowledged across the health sciences, relatively little has been done to enforce strict laws to address this public health concern. Researchers need to broaden the evidence base on outdoor smoking, with a particular focus on studies that distinguish between the effects of outdoor and indoor smoking and how each affects the health of passive smokers. Future studies should also examine how public attitudes toward smoking in public versus private settings continue to evolve (Kaufman et al., 2010).

References

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Alesci, N.L., Forster, J.L., Blaine, T., 2003. Smoking visibility, perceived acceptability, and frequency in various locations among youth and adults. Preventive Medicine 36, 272–281.

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