title: Sample design, sample augmentation, and estimation for Wave 2 of the NSHAP.
abstract: OBJECTIVE
  The sample for the second wave (2010) of National Social Life, Health, and Aging Project (NSHAP) was designed to increase the scientific value of the Wave 1 (2005) data set by revisiting sample members 5 years after their initial interviews and augmenting this sample where possible.
  
  
  METHODS
  There were 2 important innovations. First, the scope of the study was expanded by collecting data from coresident spouses or romantic partners. Second, to maximize the representativeness of the Wave 2 data, nonrespondents from Wave 1 were again approached for interview in the Wave 2 sample.
  
  
  RESULTS
  The overall unconditional response rate for the Wave 2 panel was 74%; the conditional response rate of Wave 1 respondents was 89%; the conditional response rate of partners was 84%; and the conversion rate for Wave 1 nonrespondents was 26%.
  
  
  CONCLUSIONS
  The inclusion of coresident partners enhanced the study by allowing the examination of how intimate, household relationships are related to health trajectories and by augmenting the size of the NSHAP sample size for this and future waves. The uncommon strategy of returning to Wave 1 nonrespondents reduced potential bias by ensuring that to the extent possible the whole of the original sample forms the basis for the field effort. NSHAP Wave 2 achieved its field objectives of consolidating the panel, recruiting their resident spouses or romantic partners, and converting a significant proportion of Wave 1 nonrespondents.
authors.affiliation: University of Chicago Harris School and NORC and caomuirc@uchicago.edu.
authors.forename: Colm
authors.initials: C
authors.lastname: O'Muircheartaigh
authors.affiliation: NORC at the University of Chicago, Illinois.
authors.forename: Ned
authors.initials: N
authors.lastname: English
authors.affiliation: NORC at the University of Chicago, Illinois.
authors.forename: Steven
authors.initials: S
authors.lastname: Pedlow
authors.affiliation: NORC at the University of Chicago, Illinois.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Kwok
mesh_terms: D000368:Aged / Q000523:psychology / Q000706:statistics & numerical data; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003625:Data Collection / Q000379:methods; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010352:Patient Dropouts; D012107:Research Design; D012494:Sampling Studies; D018454:Spouses / Q000523:psychology / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology
keywords: Longitudinal survey design; NSHAP Wave 2; Panel attrition; Panel survey; Panel weighting; Partner reports.