Nielsen today is releasing a first-of-its-kind in-depth look at households with people who have disabilities, finding that while they skew lower income, they actually make more shopping trips and spend more per trip on average than other households.

The research giant's first State of the Disabled Consumer report finds households with disabled members over index in shopping at gas stations and convenience stores, dollar stores and mass merchandisers and under index in other channels, particularly club stores.

The research from more than 46,000 respondents in Nielsen's HomeScan consumer panel finds 35% of U.S. households have someone with a disability, including more than 20 million with physical disabilities and nearly 4 million with intellectual disabilities. Nielsen estimates that these households rank just behind baby boomers and the older "mature" segment in terms of largest U.S. consumer segments.

Nielsen concludes households with disabilities are more brand loyal than others, because they're 11%-12% less likely than average to use coupons or buy products on off-price deals.

But the households skew lower income. A remarkable 58% of households with under $20,000 in annual income have someone with a disability, according to Nielsen. Indeed, the study shows a strong inverse correlation between disabilities and income, with each higher income tier having a smaller percentage of households with disabilities than the one below, and only 21% of households with incomes over $100,000 having someone with a disability.

The product category that these households over-index for most is tobacco and related accessories. Not surprisingly, disability households also over index for buying medications.

They're also above average for pet ownership and thus purchases of pet food and products, though they under index for shopping at pet specialty retailers. So the disabilities market is particularly big for pet brands sold at mass-merchandise outlets such as Walmart and dollar stores but with lower sales in pet specialty.

As with other lower-income households, those with disabled family members also over index for purchases of carbonated soft drinks and frozen prepared foods, according to Nielsen. But they under index for purchases of most personal-care product categories. And because households with the disabled are less likely to have children under 6, they also significantly under index on purchases of baby products.

The Nielsen research follows a 2014 call by the group DisABILITYincites for market researchers to do more to represent people with disabilities in survey research. The group believes the disabled aren't adequately represented in surveys, panels and other research because those tools aren't expressly designed to include them in samples.