†Obtained from AQoL publication [ 17] and based on equivalent midpoint age used in the model.
Years since diagnosis was calculated by subtracting the midpoint age of the age groups of diagnosis from the age at baseline.
Following preliminary meta-regressions (not shown), a "basic model" was fitted which included eight categorical variables (sex, continent, outcome subtype, how asthma was taken into account, smoking product, unexposed base group, adjustment for age, and adjustment for factors other than age or sex) and also midpoint age, a continuous variable estimated from the age range of the population.
Conception dates of the calves were estimated on the basis of the midpoint age per age cohort (i.e. 1.5, 4.5, 7.5, 10.5, 15 and 21 months for the 1998 data and 2 months for the 1982-1983 dassumingsuming a gestation period of 340-343 days [ 25, 58].
Age of pubertal onset was assigned to the midpoint between age at the previous visit and age at the visit at which onset was noted.
I formed the midpoint in age between her and the youngest, an affectionate, gamine German teenager named Lina who was working there for the summer until she returned to high school in Dusseldorf.
After alignment of the epidemic locally, age-specific composite epidemic curves were created by aggregation of cases by the day relative to the local midpoint and age group.
The calculations used the midpoint of age groups in some parts of the calculations (e.g. life expectancy for 70 year olds) and broader age groups for other parts of the calculation (proportion registered severely sight impaired) because the data was collected from a range of sources.
We obtained birth cohorts by subtracting age (midpoint of 5-year age band) from the central year of 5-year calendar period of diagnosis.
In this study, we use the annual COPD mortality rates as a function of age (taken to be the midpoint of the age groups).
