We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Editor's Correspondence |

Another Look at a Meta-analysis of Zinc Salts Lozenges and the Common Cold

Jeffrey L. Jackson, MD, MPH
Arch Intern Med. 1998;158(9):1038-1040. doi:.
Text Size: A A A
Published online


In reply

I greatly appreciated Mossad's thoughtful comments. I agree that inoculation studies are a valid method of studying colds. However, since there is evidence that upper respiratory tract infections from nasal inocula may have a different time-course than those obtained de novo, they should probably not be combined in a meta-analysis evaluating cold symptoms at a specific point.

Meta-analysis is a powerful analytic tool but can be subject to abuse and misinterpretation if not applied carefully.1 Meta-analysis is most useful either in combining a number of homogeneous studies not individually powerful enough to show statistical significance, or in dissecting outcomes not central to the original investigation, but important and unlikely to merit a randomized controlled trial. With regard to our meta-analysis of the effects of zinc on the common cold, the simple fact is that there was a great deal of heterogeneity between the different trials. With such heterogeneity, results from meta-analysis should be viewed skeptically, and the focus should be on determining the underlying reasons for such disparate results.


Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

First Page Preview

View Large
First page PDF preview





May 11, 1998
Samuel Dagogo-Jack, MD
Arch Intern Med. 1998;158(9):1038. doi:.
May 11, 1998
Jeffrey L. Jackson, MD, MPH
Arch Intern Med. 1998;158(9):1038-1040. doi:.
May 11, 1998
Sherif B. Mossad, MD
Arch Intern Med. 1998;158(9):1038-1040. doi:.
Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.


Some tools below are only available to our subscribers or users with an online account.

0 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

See Also...