Table 3

 Characteristics and outcomes of non-randomised controlled studies

First authorDesignInclusion criteria (study and comparison group)Treatment characteristics and group sizeAge at inclusion (y)Outcome assessmentOutcomeT±Ads at follow upControl group at follow upRisk difference with 95% CI (% improvement or episodes/year)Risk ratio (and 95% CI)
*Outcome not more precisely defined.
†Baseline differences; CI not calculated.
Kaiser (1926) (as Kaiser 1924)Prospective follow upT+Ads: Children who had obvious diseased tonsils and adenoids and who underwent T+Ads Control group: parents refused T+AdsT+Ads: 1200 Control: 1200T+Ads and control: 4 to 73 yearsPresence of complaints:
Frequent sore throat*5%49%−44% (−47 to −40%)0.11 (0.09 to 0.14)
URI: frequent head colds and ear trouble*12%51%−39% (−42 to −36%)0.24 (0.20 to 0.28)
Frequent fever attacks*4%3%2% (0.4 to 3%)1.7 (1.1 to 2.7)
Kaiser (1930) (as Kaiser 1931 and 1940)Prospective follow upAs Kaiser 1926T+Ads: 2200 Control: 2200T+Ads and control: 4 to 710 yearsPresence of complaints:
Frequent sore throat*10%36%−25% (−28 to −23%)0.29 (0.25 to 0.33)
URI: frequent head colds and ear trouble*22%31%−9% (−11% to −6%)0.72 (0.66 to 0.8)
Frequent fever attacks*5%5%0.1% (−1% to 1%)1.0 (0.8 to 1.3)
Monroe (1930)Prospective follow upBroad inclusion criteria Author states that T+Ads and control group are comparableTE: 736 Control: 7414–13TE group: 3–18 months Controls: 12 monthsFrequent colds and sore throat still present as at inclusion*14%58%−44% (−49% to −40%)0.24 (0.2 to 0.29)
Roydhouse (1970)Prospective follow upT+Ads: recurrent attacks of tonsillitis and other respiratory infections Control group: hospital waiting listT+Ads: 252 Control: 175T+Ads and control: 6.1After 1 and 2 yearsSore throat episodes*0.4/year2.1/year−1.7 (−1.8 to −1.5)0.21 (0.18 to 0.24)
URI episodes*1.35/year1.36/year0.02 (−0.2 to 0.2)1.0 (0.89 to 1.14)
Sore throat associated days school absence*0.87/year3.8/year−3.0 (−3.2 to −2.7)0.23 (0.21 to 0.26)
Roos (1978) (as Roos 1979)Retrospective; data from databaseT±Ads and control group: one doctor’s diagnosis of tonsillitis, peritonsillar abscess, or hypertrophy in the year before inclusionT±Ads: 1950 Control: 2089T+Ads and control: <13After 1 yearDoctors visit for respiratory diagnosis0.570.76−0.19†0.75†
Henteleff (1981)Retrospective; data from databaseAs Roos 1978T±Ads: 2233 Controls: 2670T+Ads and control: <134 yearsTotal number of respiratory diagnosis in the 4 follow up years (from database)0.45/year0.52/year−0.07†0.87†
Paradise (1984)Prospective follow up; allocation according to parental preferenceInclusion criteria as RCT Paradise 1984, but children were assigned according to parental preferenceT±Ads: 52 Control: 44T±Ads: 7.9 Control: 7.6After 1, 2, and 3 whole yearsSore throat episodes (definition as RCT Paradise 1984)1.51/year2.88/year−1.4 (−1.8 to −0.9)0.52 (0.42 to 0.64)
Sore throat associated school absence (definition as RCT Paradise 1984)5.4/year6.2/year−1.0 (−1.8 to −0.2)0.84 (0.73 to 0.96)