Table 5

Cosinor analysis of incidence of sudden infant death syndrome in Sweden by periods of different incidence

Period R a b c Maximum events at peak Peak p value
Part one
Norvenius0.40528.376−3.5812.7183225 Jan>0.2
Wennergren et al 0.7775.848–4.884–3.3751113 Jan<0.01
NESS0.7509.9163.1240.7711320 Nov<0.01
Part two
1973–19800.66431.583–6.113–2.9593720 Dec <0.02
1981–19920.951100.83349.740–44.23615015 Jan <0.001
1993–19960.25113.9171.2051.3001515 Oct>0.2
  • Fitted function: f(φ) = a + b cos (φ+c).

  • R = correlation coefficient.