Because all the cases recruited were of Chinese Han nationality, the variable of ethnic origin could not be used in our analysis.
First, we expected variables representing poor reachability/contactability (moves, foreign nationality) or variables associated with time-related and logistic barriers (school age of child, single parenthood, large distances) to be overrepresented in non-participating families.
Bivariate associations between socio-demographic variables such as age, sex, and nationality and the variable "reaction" (to the questionnaire) were analysed by means of Chi Square Tests.
9We also estimated specifications (3) and (4) using a nationality based immigration variable (instead of country of birth).
The variable nationality of origin (South African/Mozambican) records the different origins of the study population.
Besides health status, the severity of the main health problem, and the status of medication use, we also included gender and nationality as independent variables for multiple linear regression analyses, because these variables differed by health status group (see Table 1).
Data check revealed no missing data for the variables nationality, municipality name and municipality number.
Insignificant control variables: nationality, children, age, serious illness among family or friends, acute disease, social commitment, parental schooling years.
Besides nationality, the independent variables were: gender, age band (16 44, 45 64, 65 74, 75 84, >85 years), time since diagnosis (dichotomized as ≤3 y and >3 y), and the Charlson index on the first level of the hierarchical structure, and HD on the second level.
