Hi Liz, My basis for this opinion comes from looking at other population studies that have similar (retrospective designs) and then (usually much smaller) studies from the same populations that have prospective designs. When you have retrospective studies you underestimate the exposure to infant formula. The CDC study asks parents to remember back a minimum of a year and a half and a maximum of 3 years- we know that such retrospective designs does not give accurate data on exclusivity (but does on any breastfeeding). And then there's personal observation- just from the people I know very, very few infants are not given infant formula at some point even when their mothers are rabid breastfeeders. According to the US CDC data half of babies breastfeeding at 6 months of age have never been exposed to infant formula, not once in their life....that's an impressive stat, does that gel with your experience?? Karleen Gribble Australia -----Original Message----- From: Lactation Information and Discussion [mailto:[log in to unmask]] On Behalf Of Elizabeth Brooks Sent: Tuesday, 15 February 2011 1:35 PM To: [log in to unmask] Subject: Re: Medela, Advertising and commercialisation [and BF studies] Karleen, I'm not a statistician nor epidemiologist. But I took a look at the CDC's survey methods used to collect the data to arrive at rates for BF initation, exclusivity and duration (at http://www.cdc.gov/breastfeeding/data/NIS_data/survey_methods.htm ) -- including the wording of the questions they used to collect the BF data. The qeustions were part of the [US] National Immunzation Survey. The sample is pretty big: "This nationwide survey provides current national, state, and selected urban-area estimates of vaccination coverage rates for U.S. children ages 19 to 35 months. Since July 2001, breastfeeding questions have been asked on the NIS to assess the population's breastfeeding practices." When you look at the page above, the BF questions are listed right there ... including how the wording was tweaked in different years to "get at" that exclusivity notion. I think the CDC (which does use statisticians and epidemiologists) would be alarmed to realize they got it wrong by as much as 8 percentage points. They report 13% exclusive BF at 6 months; your post suggests the number is closer to 5%. What is the basis for your conclusion that 5% is the more accurate rate? Liz Brooks JD IBCLC FILCA Wyndmoor, PA, USA *********************************************** Archives: http://community.lsoft.com/archives/LACTNET.html To reach list owners: [log in to unmask] Mail all list management commands to: [log in to unmask] COMMANDS: 1. To temporarily stop your subscription write in the body of an email: set lactnet nomail 2. To start it again: set lactnet mail 3. To unsubscribe: unsubscribe lactnet 4. To get a comprehensive list of rules and directions: get lactnet welcome *********************************************** Archives: http://community.lsoft.com/archives/LACTNET.html To reach list owners: [log in to unmask] Mail all list management commands to: [log in to unmask] COMMANDS: 1. To temporarily stop your subscription write in the body of an email: set lactnet nomail 2. To start it again: set lactnet mail 3. To unsubscribe: unsubscribe lactnet 4. To get a comprehensive list of rules and directions: get lactnet welcome