Table 4.

Robustness Checks: Impact of H1N1 on Other Outcomes, 2008 vs 2009.

Panel A. Impact of H1N1 on Select Measures of Hospitalizationsa
	(1) Known/Unknown Causes of Diarrheab	(2) Hospitalizations due to Injuriesc	(3) Hip-related Proceduresd	(4) Total Hospital Discharges: excl. H1N1
H1N1e	0.0004	0.005	0.089	0.123
	(0.001)	(0.007)	(0.033)	(0.146)
p-value f	0.830	0.782	0.903	0.898
R2	0.026	0.033	0.264	0.037
Mean $\left({\displaystyle \overline{Y}}\right)$	14.23	831	2,055	15,840
Obs.	64	64	64	64
Age Group	0–4	0–4	All	0–4

Panel B. Impact of H1N1 on Select Morbidity and Mortality Measuresg
	(1) Known/Unknown Causes of Diarrhea Casesb	(2) Conjunctivitish	(3) Mortality (Deaths)
H1N1e	0.0004	−0.042	0.0003
	(0.0003)	(0.039)	(0.002)
p-value f	0.136	0.334	0.925
R2	0.137	0.054	0.324
Mean $\left({\displaystyle \overline{Y}}\right)$	11.5	2742	34
Obs.	64	64	64
Age Group	0–4	0–4	0–4

Notes: All regressions include time and state fixed effects; period of analysis is 2008–2009. Mean $\left({\displaystyle \overline{Y}}\right)$denotes the mean of the dependent variable for each specification and for the period of analysis.

^aThe dependent variable is annual hospital discharges as specified in each column.

^bKnown causes include International Classification of Diseases (ICD-10) A00-A08; Unknown causes include ICD-10 code A09X.

^cInjuries include ICD-10 codes S00-S798.

^dHip-related procedures include codes that capture fracture of femur (S72), arthrosis of hip (M16), complications of surgical and medical care (T80-T85), presence of orthopedic joint implants (Z96.6), fracture of bone following insertion of orthopedic implant (M96.6), and fitting and adjustment of orthopedic device (Z46.7).

^eH1N1 denotes the number of confirmed H1N1 cases in a given state during the treatment period (2009), and zero otherwise (2008).

^fp-value denotes the p-value of wild bootstrapped standard error to correct for small number (32) of clusters.

^gThe dependent variable is the annual number of diarrhea cases or deaths due to diarrhea as specified in each column.

^hConjunctivitis includes ICD-10 codes B30 and H10.