Description

For sample adults age 18+ who have at least one functional activity limitation (FLANY), and for whom a fatigue problem was reported as a condition causing any functional activity limitation (FLFATIG), FLFATIGMO reports the duration, in months, of the fatigue problem.

Data on the duration of a limiting fatigue problem were collected via the question, "How long have you had [a fatigue problem]?" Respondents could answer this open-ended question using the time unit of their choice (i.e., days, weeks, months, years, or since birth). The original responses to the question are reported in two complementary variables, FLFATIGTP (which specifies the time unit) and FLFATIGNO (which reports the number of such units). For the NHIS public use files, the National Center for Health Statistics (NCHS) recoded the results from these two variables to create two other variables using standard time units: years (FLFATIGY) and groups of months (FLFATIGMO).

The 1997 forward NHIS Survey Descriptions caution that because the ad hoc classified condition categories (such as a "fatigue problem" (FLFATIG)) were not included on flashcards given to respondents during the course of the interview, it is possible that weighted frequencies for these conditions may be underestimated. Thus, the NCHS recommends that "these variables should be analyzed with care."

Comparability

Apart from a change in the coding of "unknown" cases, this variable is comparable across years.

Analysts can achieve comparability across all years by combining codes with a common first digit of 9 into a single "unknown" category.

Universe

Availability

• 1997-2018

Weights

• 1997-2018 : SAMPWEIGHT