Basics of study design: Practical considerations

EXAMPLES OF RESEARCH PROJECTS BY FELLOWS

The following are examples of well-written statements of study purpose from actual studies conducted by our fellows.

Device evaluation

Defining “Flow Starvation” in volume control mechanical ventilation.

• The purpose of this study is to evaluate the relationship between the patient and ventilator inspiratory work of breathing to define the term “Flow Starvation.”

Auto-positive end expiratory pressure (auto-PEEP) during airway pressure release ventilation varies with the ventilator model.

• The purpose of this study was to compare auto-PEEP levels, peak expiratory flows, and flow decay profiles among 4 common intensive care ventilators.

Patient study

Diaphragmatic electrical activity and extubation outcomes in newborn infants: an observational study.

• The purpose of this study is to describe the electrical activity of the diaphragm before, during, and after extubation in a mixed-age cohort of preterm infants.

Comparison of predicted and measured carbon dioxide production for monitoring dead space fraction during mechanical ventilation.

• The purpose of this pilot study was to compare dead space with tidal volume ratios calculated from estimated and measured values for carbon dioxide production.

Practice evaluation

Incidence of asynchronies during invasive mechanical ventilation in a medical intensive care unit.

• The purpose of this study is to conduct a pilot investigation to determine the baseline incidence of various forms of patient-ventilator dyssynchrony during invasive mechanical ventilation.

Simulation training results in improved knowledge about intubation policies and procedures.

• The purpose of this study was to develop and test a simulation-based rapid-sequence intubation curriculum for fellows in pulmonary and critical care training.

HOW TO SEARCH THE LITERATURE

After creating a problem statement, the next step in planning research is to search the literature. The 10th issue of Respiratory Care journal in 2009 was devoted to research. Here are the articles in that issue related to the literature search:

• How to find the best evidence (search internet)⁹
• How to read a scientific research paper¹⁰
• How to read a case report (or teaching case of the month)¹¹
• How to read a review paper.¹²

I recommend that you read these papers.

Literature search resources

My best advice is to befriend your local librarian.¹³ These people seldom get the recognition they deserve as experts at finding information and even as co-investigators.¹⁴ In addition to personal help, some libraries offer training sessions on various useful skills.

PubMed

The Internet resource I use most often is PubMed (www.ncbi.nlm.nih.gov/pubmed). It offers free access to MEDLINE, which is the National Library of Medicine’s database of citations and abstracts in the fields of medicine, nursing, dentistry, veterinary medicine, health care systems, and preclinical sciences. There are links to full-text articles and other resources. The website provides a clinical queries search filters page as well as a special queries page. Using a feature called “My NCBI,” you can have automatic e-mailing of search updates and save records and filters for search results. Access the PubMed Quick Start Guide for frequently asked questions and tutorials.

SearchMedica.com

The SearchMedica website (www.searchmedica.co.uk) is free and intended for medical professionals. It provides answers for clinical questions. Searches return articles, abstracts, and recommended medical websites.

Synthetic databases

There is a class of websites called synthetic databases, which are essentially prefiltered records for particular topics. However, these sites are usually subscription-based, and the cost is relatively high. You should check with your medical library to get access. Their advantage is that often they provide the best evidence without extensive searches of standard, bibliographic databases. Examples include the Cochrane Database of Systematic Reviews (www.cochrane.org/evidence), the National Guideline Clearinghouse (www.guideline.gov), and UpToDate (www.uptodate.com). UpToDate claims to be the largest clinical community in the world dedicated to synthesized knowledge for clinicians and patients. It features the work of more than 6,000 expert clinician authors/reviewers on more than 10,000 topics in 23 medical specialties. The site offers graded recommendations based on the best medical evidence.

Portals

Portals are web pages that act as a starting point for using the web or web-based services. One popular example is ClinicalKey (www.clinicalkey.com/info), formerly called MD Consult, which offers books, journals, patient education materials, and images. Another popular portal is Ovid (ovid.com), offering books, journals, evidence-based medicine databases, and CINAHL (Cumulative Index to Nursing and Allied Health Literature).

Electronic journals

Many medical journals now have online databases of current and archived issues. Such sites may require membership to access the databases, so again, check with your medical library. Popular examples in pulmonary and critical care medicine include the following:

• American Journal of Respiratory and Critical Care Medicine (www.atsjournals.org/journal/ajrccm)
• The New England Journal of Medicine (www.nejm.org)
• Chest (journal.publications.chestnet.org)
• Respiratory Care (rc.rcjournal.com)

Electronic books

Amazon.com is a great database search engine for books on specific topics. It even finds out-of-print books. And you don’t have to buy the books, because now you can rent them. Sometimes, I find what I wanted by using the “Look Inside” feature for some books. Note that you can look for books at PubMed. Just change the search box from PubMed to Books on the PubMed home page. Of course, Google also has a book search feature. A great (subscription) resource for medical and technical books is Safari (https://www.safaribooksonline.com). Once again, your library may have a subscription.

General Internet resources

You probably already know about Google Scholar (scholar.google.com) and Wikipedia.com. Because of its open source nature, you should use Wikipedia with caution. However, I have found it to be a very good first step in finding technical information, particularly about mathematics, physics, and statistics.