1: What is the source?

The source of the article is the newspaper or online journal in which the story is published. Think about the credibility of the media source. The source is also where the results were originally published. In this case, the results were first reported in the American Journal of Medicine, the official journal of the Alliance for Academic Internal Medicine. You can find additional information about the journal by performing an internet search with the journal's name.

2: Who conducted the study?

John Hopkins University researchers.

Note: Learning who conducted the study can help you to determine if there was any bias in the study.

3: Who were the participants?

10,000 participants from a national study, the National Health and Nutrition Examination Survey, which itself is conducted by the Centers for Disease Control and Prevention.

NOTE: This is a large sample size, which suggests that it is likely to be representative of the whole population of the country. Please note that the article does not report additional details about the participants. Were they young or old? Were they mostly white? Were there equal numbers of women and men? The answers to these questions would tell you whether or not these results could apply to you.

6: Who funded the study?

The National Heart, Lung and Blood Institute, which is part of the National Institutes of Health.

Note: Again, knowing who funded the study can help determine if there is any bias in the study. In this case, funding from the National Heart, Lung, and Blood Institute means that the study has been reviewed by peer researchers and is not unlikely to have bias that may be introduced when the funder is a corporation.

4: What happened in the study?

The researchers compared the NHANES survey data with mortality data. Note that the results reported here are survey data, and not results from a clinical research trial.

7: Was the study completed?

Whether or not the study was completed is not explicitly stated in this article. However, because they were using survey data, and not conducting a clinical trial, we can infer that the publication of the results in a scientific journal implies completion of the study.

5: What did they learn?

People whose vitamin D levels are at the top end of the what the Institute of Medicine considers adequate and at the low end of what the Institute of Medicine considers normal cut their risk of death in half. Though it is not explicitly stated in the article, we assume that this lower risk of death is compared to people whose vitamin D levels were below the low-normal or upper-adequate range. People whose vitamin D levels were above upper-adequate or low-normal did not have any added protection against death

1: What is the source?

The newspaper or journal reporting the results is one source. The second source is the scientific journal in which the results were originally published, in this case the Journal of the American Medical Association, the offical journal of the American Medical Association (AMA).

2: Who conducted the study?

Duke University researchers.

3: Who were the participants?

The article provides limited information about the participants. It tells us they were diagnosed with coronary artery disease and myocardial ischemia and that there were 112 patients.

NOTE: Note that the article does not include information about participants' age, gender or race. Think about what the number of participants in the study might mean for how applicable the results are for a broader population.

2: Who conducted the study?

Dr. Wei Jiang was the lead researcher. He is from Duke University.

5: What did they learn?

Here is one result of the study.

7: Was the study completed?

We are not given a direct answer to this question, but we might guess that it was completed for two reasons: 1) the article does not say it was NOT completed (typically, if a study is not completed, the article will state that), and 2) when researchers publish their results in a scientific journal, they typically do so after their study has reached a level of completion.

4: What happened in the study?

Here, we are given the basics of the study design.

5: What did they learn?

A second result. Though we are not given any additional information about this result, we can infer that researchers also asked the participants to engage in some form of physical exercise, and compared the number of patients in each group (anti-depressant group and placebo group) who experienced myocardial ischemia.