pain/penetration force

insertion speed

Aronson 2012

no effect on pain frequency

effect on pain quality

slow insertion (120mm/min) --> dull pain

fast insertion (1140mm/min) --> sharp pain (most common)

insertion angle

gender

Aronson 2012

men --> higher pain

women --> lower pain

Aronson 2012

low angle (45°) --> high pain

high angle (90°) --> low pain

anatomical region

Aronson 2012

effect on pain

Egekvist 1999

no effect on pain frequency

from thigh to deltoid to abdomen --> PF declined

thigh --> high PF

abdomen --> low PF

Egekvist 1999 - Pain & Mechanical Injury

no effect on pain

Egekvist 1999 - Pain & Mechanical Injury

slow insertion (120mm/min) --> low PF

fast insertion (1140mm/min) --> high PF

needle tube/diameter

Gill 2007

Egekvist 1999 - Pain & Mechanical Injury

small needle size (30G) --> low PF / low frequency of occurence of pain

big needle size (27G) --> high PF / high frequency of occurence of pain

needle gauge effects the frequency of pain

needle tip sharpness

lubrication

Gill 2007

reduction of force & workload possible --> reduced pain

Gill 2007

reduction of force & workload possible --> reduced pain

Arendt-Nielsen 2006

decreased OD --> frequency of pain can be reduced

Chantelau 1991

needle tip geometry

Norman 2012

blinded comparison 5bevels vs. 3bevels: no difference for pain, ease of insertion

blinded comparison: reduction of insertion force with 5bevels not easily distinguished by patients

Norman 2012

abdomen & thigh are the least sensitive areas for tactile discrimination

not blinded comparison: 5bevels --> easier insertion, less painful, more comfortable

Praestmark 2016

PF & SBP increased with needle diameter

Pain intensity not significantly increase with needle diameter

Praestmark 2016

for 32G & 34G: blinded perception of pain intensity does not differ between needle design

needle length

Schwartz 2004

Iwanaga 2009

diameter plays an important role in reducing injection pain and needle anxiety

Valentini 2014

less pain with 33Gx4mm than with 32Gx4mm

reuse

Puder 2004

reuse up to 5 times --> no progressive tip deformity, no increased pain intensity or unpleasantness

Misnikova 2011

reuse up to 7 times --> bacterial contamination, local inflammatory changes, injection pain increase in proportion to needle reuse

Zabaleta-del-Olmo 2016

no clear scientific evidence for or against reuse

novofine 32G 6mm (conical) vs. micro fine plus 31G 5mm --> novofine more convenient, easy to use, less painful, less bleeding/bruising/leakage

McKay 2009

novofine 32G 6mm vs. novofine 30G 8mm: preference for 32G, less painful

31G x 6mm vs. 29G x 12,7mm: no differences in glycemic control, pain & leakage

Schwartz 2004

31G x 6mm vs. 29G x 12,7mm: no differences in glycemic control, pain & leakage

Schuler 1992

reuse up to 12 times --> no contamination of needle. but half of the needles plastic ground, no infection at injection sites

recommend reuse of pen needles as a simple, safe and cost-beneficial procedure (limited to 5 to 10 injections --> needles point becomes more and more blunt, causes pain)

33000 injections in total (1, 3, 6, 9, 12 times)

Haindl 1988

no recommendation of multiple use --> dullness & deflection of needle tip

Miwa 2012

open-label, controlled home use study: 32G x 6mm (conical 3bevels tip) & 32G x 4mm (3bevels) --> equivalent controlling of glycemic levels

more leakage and bleeding for 4mm (not significant)

4mm needle is less painful, easier to insert, preference on the whole

Miwa 2012

4mm needle is less painful, easier to insert, preference on the whole

more leakage and bleeding for 4mm (not significant)

open-label, controlled home use study: 32G x 6mm (conical 3bevels tip) & 32G x 4mm (3bevels) --> equivalent controlling of glycemic levels

Hirsch_Gibney 2012

reduced pain of 32G x 4mm vs. 31G x 5mm and 8mm

equivalent glycemic control in obese and non-obese patients

Hirsch_Gibney 2012

reduced pain of 32G x 4mm vs. 31G x 5mm and 8mm

equivalent glycemic control in obese and non-obese patients

Berard 2014

open-label study with 66 obese patients, 6 month: 31G x 5mm vs 8mm: no difference in pain or less pain with 5mm

differences in pain reported are associated with needle length

5mm was more comfortable, easier to use, equally effective in delivering insulin

Aronson 2013

ETW 5bevel vs. similar size TW? 3bevel??: improved flow and pressure, easier to use, lower thumb force, reduced pain, leakage was less

Dau 2017

significantly less injection pain with scalpel bevel design than for triple bevel and regular bevel (dental needle)

more hooks with scalpel bevel design

Mayer 2009

3 bevel 30G vs. 5bevel 29G & 27G

5bevel: additional tipping results in higher piercing resistance and shorter cuts, enlarged coring tendency

Omoigui 2006

same size, diameter and length: 3facet grind (Terumo) vs. 3facet grind, low angle bevel (BD): with BD less pain

Kursat 2013

intensity of pain increased significantly with increasing needle length (4mm vs. 8mm)

Strock 2013

4mm PN less painful than 8mm in high-dose subjects

Bergenstal 2015

4mmx32G vs. 8mmx31G vs. 12,7mmx29G ??? --> 4mm favorable findings for pain, ease of use, overall patients preferences

Saito 2014

G34x4mm vs. G31x5mm vs. G32x6mm

first G31 or G32 then G34

pain improvements with G34, could also be related to needle length (improvement greater with G32)

Steele 2012

bevel design influences the forces required to insert and withdraw dental needles in vitro