Table 6.

Pneumococcal vaccination studies examining antimicrobial use in children: observational studies.

Reference	Design	Population	N	Age	Vaccine	Outcome description	Outcome						Direction effect (−, −/+. +)
							Measure		Outcome		95% CI/ p-value
Eythorsson [35]	Population-based	Birth cohort – children	50,570	<3 yrs	PHiD-CV10	Null antimicrobial prescriptions	IRR		1.16		1.10–1.23		+
					PHiD-CV10	1–4 antimicrobial prescriptions	IRR		1.08		1.06–1.11		−
					PHiD-CV10	5–9 antimicrobial prescriptions	IRR		0.92		0.89–0.95		+
					PHiD-CV10	10–14 antimicrobial prescriptions	IRR		0.77		0.72–0.82		+
					PHiD-CV10	≥15 antimicrobial prescriptions	IRR		0.83		0.74–0.93		+
				0–5 mo	PHiD-CV10	Antimicrobial prescriptions	IRR		0.82		0.79–0.85		+
				6–11 mo	PHiD-CV10	Antimicrobial prescriptions	IRR		0.84		0.83–0.86		+
				12–17 mo	PHiD-CV10	Antimicrobial prescriptions	IRR		0.93		0.91–0.94		+
				18–23 mo	PHiD-CV10	Antimicrobial prescriptions	IRR		0.94		0.92–0.96		+
				24–29 mo	PHiD-CV10	Antimicrobial prescriptions	IRR		0.87		0.85–0.89		+
				30–35 mo	PHiD-CV10	Antimicrobial prescriptions	IRR		0.89		0.86–0.91		+
Fortanier [36]	Population-based	Infants	255,154	<2 yrs	PCV7/PCV10**	Antimicrobial purchases	RR		0.984		0.977–0.992		+
Howitz [37]	Population-based	Children	1.04–1.08 million	0–15 yrs	PCV7	Antimicrobial prescriptions	IRR		0.9542		0.9536–0.9548		+
				0–15 yrs	PCV13	Antimicrobial prescriptions	IRR		0.9048		0.9043–0.9052		+
Johansson Kostenniemi [42]	Population-based	Whole population	259,183	All ages	PCV7/PCV13	Antimicrobial prescriptions	Decrease#		NR		–		+
				All ages	PCV7/PCV13	Antimicrobial Prescription for URI	Decrease#		37.1%		NR		+
				0–4 yrs	PCV7/PCV13	Antimicrobial Prescription for pneumonia	Decrease#		28.6%		NR		+
Kinlaw [38]	Population-based	Birth cohort- infants	561,729	≤1 yr	PCV7/PCV13	At least one antimicrobial prescription	1-year risk		4.4%		3.4% to 5.5%		+
Lau [39]	Population-based	Children	567,275	<10 yrs	PCV7/PCV13	Antimicrobial prescriptions for OM	Decrease***		72.9%		–		+
					PCV7	Antimicrobial prescriptions for OM	ITS analysis		18.9%		16.0%−21.7%		+
					PCV13	Antimicrobial prescriptions for OM	ITS analysis		12.2%		8.6%−15.6%		+
Palmu [40]	Population-based	Birth cohort- Children	NR	<4.5 yrs	PCV10	Antimicrobial prescriptions	RR		17.5%		17.0%−18.1%		+
Zhou [41]	Population-based	Infants	20,628/153,812*	<2 yrs	PCV7	Antimicrobial prescriptions for AOM	Decrease		41.9%		–		+
							Absolute difference		522		513–530 <.001		+

*1997: N = 20,628; 2004: N = 153,812; **PCV7 compared with PCV10; *** 2002 versus 2012; # results presented in text; AOM: acute otitis media; CI: confidence interval; IRR: incidence rate ratio; mo:months; NR: not reported; OM: otitis media; PHiD-CV10: pneumococcal Haemophilus influenzae protein D conjugate vaccine; PCV7: heptavalent pneumococcal conjugate vaccine; PCV10: 10-valent pneumococcal conjugate vaccine; PCV13: 13-valent pneumococcal conjugate vaccine; RR: rate ratio; SIGN: Scottish Intercollegiate Guidelines Network; URI: upper respiratory illness; yr(s): year(s); ITS: Interrupted time series.