Table 1.

Response Rates Within Subgroups

Responders (Overall Response = 644/873)
CharacteristicNumber*Percent With Characteristic
* Because of missing values from sent questionnaires, for which assistants collected baseline characteristics but forgot to fill in some of the data, the number of usable questionnaires ranged from 862 to 871.
† Response rate increasing with age, P <.001 (χ2 for trend).
‡ Response rate higher for patients with chronic illness P <.001 (χ2).
§ Response rate increasing with higher contact frequency, P <.016 (χ2 for trend).
Age, y
    18–40182/28464
    41–60270/34977
    61–80170/21081
>8020/2483
Sex
    Female399/53375
    Male243/33872
Chronic illness
    Yes255/31481
    No380/54870
Contacts with physician in the last 12 mo (including last visit)§
    1–2122/17769
    3–4154/22170
    5–10244/31079
>10121/16275