Table 1

Case-control studies estimating the frequency of PD among relatives of cases in comparison with controls

AuthorSource of casesSource of controlsPercentage of cases with family history of diseasePercentage of controls with family history of diseaseFamilial relative risk (crude)
Martin 1973Clinic seriesCase spouses26.814.81.8
Semchuk 1993Clinic seriesAge, sex matched community22.76.33.6
Payami 1994Clinic seriesCase spouses or friends15.84.04.0
Vieregge 1995Clinic seriesNon-neuro hospital patients9.11.46.5
Bonifati 1995Clinic seriesCase spouses24.06.04.0
de Michele 1996Clinic seriesSpouses and neuro hospital patients33.03.49.7
Marder 1996Population basedCommunity volunteers6.44.91.3
Taylor 1999Clinic seriesCase in-laws or friends18.66.82.7
Elbaz 1999Population basedCommunity10.33.52.9