Figure 2. Kaplan-Meier estimates of the cumulative incidence of overt hypothyroidism in women with subclinical hypothyroidism (initial serum TSH >4 mU/l) as a function of initial serum TSH, thyroid secretory reserve in response to oral thyrotropin releasing hormone (TRH) and detectable microsomal antibodies. Serum TSH appears to be the strongest of these predictors (from reference (89)).