. 2016 Nov 25;16:711. doi: 10.1186/s12879-016-2040-y

Table 2.

Characteristics of included studies (continued)

Author, year [Ref]	Number of study groups	Safety assessment	Statistically significant differences in baseline characteristics and safety outcomes between primary and revaccination dose of PPSV-23
Prospective cohort studies (n = 10)
Tobudic, 2012¹ [31]	1 (longitudinal cohort)	7 day diary (after revaccination dose)	Population characteristics: Participants 1 year older at 2^nd dose
Tobudic, 2012¹ [31]	1 (longitudinal cohort)	7 day diary (after revaccination dose)	Safety: no comparison group
Dransfield, 2012¹ [23]	2 (1^st vs. 2^nd dose)	not assessed	Population characteristics: 2^nd dose recipients older, more often white, more severe COPD disease
Dransfield, 2012¹ [23]	2 (1^st vs. 2^nd dose)	not assessed	Safety: −
Hammitt, 2011 [11]	3 (1^st vs. 2^nd or 3^rd dose)	4 day diary and interview on day 30	Population characteristics: 2^nd/3^rd dose recipients older, more likely Alaska Natives/American Indians, more often with underlying comorbidities compared to 1^st dose recipients
Hammitt, 2011 [11]	3 (1^st vs. 2^nd or 3^rd dose)	4 day diary and interview on day 30	Safety: local AEs and systemic AEs more frequent in revaccination group
Jackson, 1999 [13]	2 (1^st vs. 2^nd dose)	13 day diary and telephone interview	Population characteristics: 2^nd dose recipients more often females and less often with underlying comorbidities
Jackson, 1999 [13]	2 (1^st vs. 2^nd dose)	13 day diary and telephone interview	Safety: local AEs more frequent in revaccination group at days 0–2, no differences after 6 days. No differences regarding systemic AEs. Multivariate analysis: revaccination independently associated with risk of sizable local reaction
Jackson, 2013 [22]	1 (longitudinal cohort)	13 day diary	Population characteristics: Participants 3.4–5 years older at 2^nd dose
Jackson, 2013 [22]	1 (longitudinal cohort)	13 day diary	Safety: local AEs and systemic AEs more frequent in revaccination group
Manoff, 2010² [25]	2 (1^st vs. 2^nd dose)	not assessed	Population characteristics: 2^nd dose recipients more likely ever smoked
Manoff, 2010² [25]	2 (1^st vs. 2^nd dose)	not assessed	Safety: −
Musher, 2010³ [12]	2 (1^st vs. 2^nd dose)	14 day diary	Population characteristics: 2^nd dose recipients more often with underlying comorbidities
Musher, 2010³ [12]	2 (1^st vs. 2^nd dose)	14 day diary	Safety: local AEs and systemic AEs more frequent in revaccination group
Musher, 2011^3,4 [28]	2 longitudinal cohorts (1^st vs. 2^nd; 2^nd vs. 3^rd)	14 day diary	Population characteristics: Participants of both longitudinal cohorts were ten years older at 2^nd/3^rd dose
Musher, 2011^3,4 [28]	2 longitudinal cohorts (1^st vs. 2^nd; 2^nd vs. 3^rd)	14 day diary	Safety⁵: local AEs and systemic AEs more frequent in revaccination group
Ohshima, 2014 [29]	1 (longitudinal cohort)	14 day diary	Population characteristics: Participants were 7.6 years older at 2^nd dose
Ohshima, 2014 [29]	1 (longitudinal cohort)	14 day diary	Safety: local AEs and systemic AEs more frequent in revaccination group
Törling, 2003 [24]	1 (longitudinal cohort)	not assessed	Population characteristics: Participants were 5.3 years older at 2^nd dose and 11% had a new episode of pneumonia
Törling, 2003 [24]	1 (longitudinal cohort)	not assessed	Safety: no comparison group
Retrospective database studies (n = 3)
Jackson, 2006 [27]	3 (1^st vs. 2^nd vs. 3^rd dose)	ICD-9-Codes	Population characteristics: 3^rd dose recipients were older and had more likely underlying comorbidities
Jackson, 2006 [27]	3 (1^st vs. 2^nd vs. 3^rd dose)	ICD-9-Codes	Safety: Presumptive medically attended injection site reaction more frequent in 2^nd dose recipients than in 1^st dose recipients. No statistically significant differences between 1^st dose and 3^rd dose recipients
Shih, 2002 [30]	2 (1^st vs. ≥ 2^nd dose)	ICD-9-Codes	Population characteristics: 2^nd dose recipients were older, more often white and had higher hospitalizations rates and a higher comorbidity (Charlson) Index
Shih, 2002 [30]	2 (1^st vs. ≥ 2^nd dose)	ICD-9-Codes	Safety: Mulitivariate analysis: Revaccination independently associated with emergency room visits and office visits if PPSV-23 was administered within 5 years. No association after >5 years.
Walker, 2005 [32]	2 (1^st or 2^nd vs. ≥ 3^rd dose)	ICD-9-Codes and medical records	Population characteristics: ≥ 3^rd dose recipients were older and had more likely underlying lung diseases
Walker, 2005 [32]	2 (1^st or 2^nd vs. ≥ 3^rd dose)	ICD-9-Codes and medical records	Safety: No differences in risk of medically attended AEs in the different groups
Cross-sectional study (n = 1; telephone interview)
D’Heilly, 2002 [26]	2 (1^st vs. ≥ 2^nd dose)	Interview 8 months (on average) after vaccination	Population characteristics: not reported
D’Heilly, 2002 [26]	2 (1^st vs. ≥ 2^nd dose)	Interview 8 months (on average) after vaccination	Safety: Multivariate analysis: Revaccination independently associated with redness or swelling at injection site during week after vaccination

¹Published as randomized controlled trial but treated as cohort study here; ²Substudy of Musher et al. [12]; ³Musher [28] is extension study of Musher et al. [12]; ⁴ two longitudinal cohorts: cohort one received 1st dose in 1997 and 2nd in 2007; cohort two received 2nd dose in 1997 and 3rd in 2007; ⁵2nd vs. 3rd dose (1st vs. 2nd dose reported in Musher [12])