My reading of : "mention whether the study has been approved by an IRB", is that approval is necessary AND if not then why - was it because 1. did you not submit it for approval (again why?) or 2. not approved once submitted  (again why?) or 3. considered exempt from approval. That is you would be required to give the reason/s for it.

I think finding a journal that bypasses IRB approval of research involving human participants (even if data confidentiality is guaranteed) may prove futile.  Any research involving human participants (and more so in case of research on psychological problems) has to be submitted to an IRB for ethical approval (one aim of an IRB is precisely to evaluate how research participants' privacy and confidentiality is protected, avoiding harms such as stigmatization, further psychological problems etc).

However, the following statement from the ICMJE (at http://www.icmje.org/recommendations/browse/roles-and-responsibilities/protection-of-research-participants.html) is instructive: 

"When reporting research involving human data, authors should indicate whether the procedures followed have been assessed by the responsible review committee (institutional and national), or if no formal ethics committee is available, were in accordance with the Helsinki Declaration as revised in 2013."

It may be a good idea to visit the website.

I hope you find it useful

Thank you for your insightful comment, Dr Aisha.

I've searched to understand better but it is still not clear.

For examples, I found some articles like these:

1. Article: The substantial burden of systemic lupus erythematosus on the productivity and careers of patients: a European patient-driven online survey

They stated: "Since this was a non-experimental, voluntary survey, no ethical approval was required"

2. Article: Since this was a non-experimental, voluntary survey, no ethical approval was required

They stated: ""As it was voluntary, reviewed current service provision and the contact list was held by a national Hiscock et al. Tobacco Induced Diseases 2014, 12:13 Page 2 of 9" http://www.tobaccoinduceddiseases.com/content/…/1/13training body, NHS ethics approval was not required".

How about these cases, are they acceptable?

You can safely assume that any reputable journal will require IRB approval. Also, I would say, journals who accept explanations like the one you cite should be flagged as highly suspicious. I would not submit an MS to them. I mean, how do they know a study is "voluntary" unless the procedures for collecting informed consent have been assessed and validated? For your research career, you should generally apply a better safe than sorry approach - as soon as humans are involved, apply to the IRB. They may then say you don't need their permission, but then you have that as your approval.

Thank you for your advice, Dr Christian.

There are good number of reports violating the rights of the study participants which is unethical. All the reputed journals not being published in the next door of your house require IRB approvals. Online surveys you are free to conduct but very difficult to get published. IRB approval states not only the validity of your study but also the valid source of data collected. Ethical approval is cleared on number of factors and one is the validity of the data source.

Thank you, Dr. Paritosh

What you are seeing in the quotations you reported is that the standard for IRB review (or ethical approval) varies considerably from country to country. Indeed, in the U.S. the standard for surveys has changed considerably in just the past few years, so that many surveys are now rated as "exempt" from review due to their voluntary and non-threatening nature.

I can't speak for other parts of the world, but it seems to me that most research-oriented universities, and medical universities in particular, are likely to have a formal committee for IRB review. So, I would recommend locating such a committee (even if it is not at your own university) and determining what their written standards are.

According to deceleration of Helsinki, It is must to get the ethical approval before doing any research involving human subjects. No matter this is online survey or interventional study. Having the Good Clinical Practice (GCP) certification of at least one researcher is also advised. The reputed journals frequently asks for IRB clearance if not mentioned in the methodology.

Thank you Dr David and Dr S M Niazur.