Bubble plot of IH rates by year of publication.

<p><b>Notes</b>: The area of each circle is proportionate to the number of patients. The line of best fit shows that IH rates increase with year of publication.</p

Univariable regression of suture type (absorbable or non-absorbable) on IH rates.

<p>^a Studies with more than one patient group available for analysis.</p><p>Summary Suture type (absorbable versus non-absorbable) had no effect on IH rates.</p><p>Univariable regression of suture type (absorbable or non-absorbable) on IH rates.</p

PRISMA diagram detailing search strategy and study selection process.

<p>PRISMA diagram detailing search strategy and study selection process.</p

Funnel plot of IH rates (y axis) by number of patients in study (x axis).

<p><b>Notes</b>: Created using Excel macro at <a href="http://www.apho.org.uk/resource/view.aspx?RID=47241" target="_blank">www.apho.org.uk/resource/view.aspx?RID=47241</a>. Dashed boundaries show ± three standard errors; feint show ± two standard errors.</p

Regression analyses of IH rates on multiple predictors.

<p>Notes: Model A: significance level for exclusion = 5%</p><p>Model B: significance level for inclusion = 10%; significance level for exclusion = 12%</p><p>Regression analyses of IH rates on multiple predictors.</p