should we promote vaginal birth for women who are ... va… · shoulder dystocia 1.0-2.0% 0%...
TRANSCRIPT
![Page 1: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/1.jpg)
SHOULD WE PROMOTE SAFE VAGINAL BIRTH
FOR WOMEN WHO ARE NULLIPAROUS, TERM,
WITH SINGLETON PREGNANCIES, AND ARE
VERTEX?
IF SO HOW AND IN WHAT MANNER?
Randall J. Morgan MD MBA
Wesley Obstetrics and Gynecology Grand Rounds March 11, 2020
![Page 2: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/2.jpg)
Nulliparous Term Singleton Vertex
• Joint Commission Core Measure – PC 02 - perinatal care
• NSTV cesarean rate = cesarean births for NTSV population
total NTSV population
NSTV population-all women with delivery of a newborn with 37 weeks or more
of gestation completed, singleton, vertex
Excluded population-< 8 years of age, > 65 years of age, length of stay > 120
days, enrolled in clinical trials, < 37 weeks,
![Page 3: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/3.jpg)
Goals
• Discuss nulliparous term singleton vertex (NTSV)
• Discuss quality improvement & high reliability concepts in our care
of nulliparous term singleton pregnancies
• Discuss quality improvement for publicly reported measures
• Discuss control charts and interpretation
• Common cause
• Special cause
• I have no conflicts of interest
![Page 4: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/4.jpg)
Risk of adverse maternal & neonalt outcomes by mode
of delivery (ACOG Safe Prevention of the Primary Cesarean Mar 2014)
Outcome risk risk
Maternal Vaginal Cesarean
Overall severe morbidity &
mortality
8.6%/0.9% 9.2%/2.7%
Maternal mortality 3.6/100,000 13.3/100,000
Amniotic fluid embolism 3.377.7/100,000 13.3/100,000
3rd 4th deg perineal 1.0-3.0% NA scheduled delivery
Urinary incontinence No diff No diff
Placental abnormality C/S increased
Neonatal
Laceration NA 1.0-2%
Shoulder dystocia 1.0-2.0% 0%
Respiratory morbidity <1.0% 1.0-4.0%
![Page 5: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/5.jpg)
Maternal morbidity and mortality associated with low-risk
planned cesarean delivery versus planned vaginal delivery at
term Liu et al CMAJ Feb 13, 2007; 176(4): 455-460
• Retrospective population-based study comparing primary cesarean
delivery for term breech (46,766) vs planned term vaginal birth(both
spontaneous & induction) (2,292,420). Study over 14 years
• Rates of maternal morbidity (cardiac arrest, wound hematoma,
hysterectomy, major puerperal infection, anesthetic complications, venous
thromboembolism, hemorrhage requiring hysterectomy, adjusted longer
hospital stay)
• Planned vaginal birth 0.9%
• Planned cesarean breech 2.7%
• Maternal mortality was not statistically different
![Page 6: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/6.jpg)
Incidence of complications with subsequent cesarean
deliveries• Placenta Previa
• risks 1/200-overall
• 1 previous cesarean risk 1% and if 3 cesareans 3%
• If previa and 3 previous cesareans - 40 chance of placenta accreta
• Uterine rupture –• Unscarred uterus- 1/5700-20,000
• Elective repeat cesarean delivery 1.6/1000
• Trial of labor- 1 low transverse 2-3/1,000
•Once uterus has scar, risks are increased whether repeat cesarean or trial of labor
![Page 7: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/7.jpg)
Independent risk factors for hemoglobin drop to <7g/dL postoperatively
Andrea Fullerton 2012 Presentation to Daniel K. Roberts society
1.00
2.00
3.00
4.00
5.00
6.00
Abnormalplacenta
Delivery at2-7 am
Preop. hgb<11
Labor priorto CS
EBL ≥1500 mL
5.50
4.85
4.03
2.612.31
Ad
just
ed
od
ds
rati
o
Hemoglobindrop to <7 g/dLpostoperatively
*P<.05**P<.001
**
*
*
**
![Page 8: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/8.jpg)
Impact of nulliparous term singleton vertex cesarean
rates are most important determinant of vaginal birth
rates
• 96% of interinstitutional variance in cesarean sections is attributable to the
nullipara term singleton cesarean rate
• >60% of the rise in cesarean rates is attributable to the nulliparous term
singleton cesarean rate
• 90% of women world-wide who have a previous cesarean will deliver future
pregnancies by cesarean (NSTV focuses on her reproductive future)
• Brennan, DJ. Am J OB GYN 2009; 201: 308 e1-8
![Page 9: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/9.jpg)
![Page 10: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/10.jpg)
https://www.statista.com/statistics/800589/us-hospital-c-section-rates-by-state/
Nebraska 34%
Kansas 25%
New Mexico 17%
US Target 23.9%
NTSV by state 2017
![Page 11: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/11.jpg)
![Page 12: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/12.jpg)
West Virginia 39%
Kansas 9th 32%
California 14.3%
Source CDC 2016
![Page 13: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/13.jpg)
![Page 14: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/14.jpg)
Wesley Medical Center 34%
South Miami 51%
Consumer Reports Analysis: Most U.S.
Hospitals’ C-Section Rates Exceeding
National Targets
A Mother’s Risk of Having a C-section
Can Vary As Much As Ninefold Across
Hospitals in the US
Filed under: Health Release date
05/16/2017
![Page 15: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/15.jpg)
If you paid $1.1 trillions annually would you feel you had
the right to determine, interpret & expect quality as you
defined quality?
• Treatment of acute MI, CHF,
pneumonia, surgical site
infections….
• Cesarean rate
• In determining quality &
utilization of resources what are
the decision rights of
• Patients
• Providers
• Hospital &institutions
• Payors?
![Page 16: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/16.jpg)
![Page 17: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/17.jpg)
![Page 18: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/18.jpg)
Maternal Morbidity and severe mortality associated with low-risk
planned cesarean delivery versus planned vaginal delivery at
term Liu et al CMAJ Feb 13, 2007; 176(4): 455-460
• Retrospective population-based study comparing primary cesarean
delivery for term breech (46,766) vs planned term vaginal birth(both
spontaneous & induction) (2,292,420). Study over 14 years
• Rates of maternal morbidity (cardiac arrest, wound hematoma,
hysterectomy, major puerperal infection, anesthetic complications, venous
thromboembolism, hemorrhage requiring hysterectomy, adjusted longer
hospital stay)
• Planned vaginal birth 0.9%
• Planned cesarean breech 2.7%
• Maternal mortality was not statistically different
How do we make
unintended
consequences
even less
common?
![Page 19: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/19.jpg)
DEBRIEF
•What surprised you about today’s discussion?
•What puzzled you about today’s conversation?
•If we were to discuss nulliparous term singleton
pregnancy and mode of delivery again, what
should we do differently?
![Page 20: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/20.jpg)
Improvement Concepts Associated with Performance
Resulting in 80-90% Process Reliability
(Primarily can be described as intent, vigilance, and hard work)
• Common equipment, standard order sheets, multiple choice protocols, and written policies/procedures
• Personal check lists
• Feedback of information on compliance
• Suggestions of working harder next time
• Awareness and training
![Page 21: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/21.jpg)
Improvement Concepts Resulting in 95%
Process Reliability
(Uses human factors and reliability science to design failure prevention, failure
identification, and mitigation)
• Decision aids and reminders built into the system
• Desired action the default (based on scientific evidence)
• Redundant processes utilized
• Scheduling used in design development
• Habits and patterns know and taken advantage of in the design
• Standardization of process
![Page 22: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/22.jpg)
Quality improvement studies
• Historical review of previous patient care
• Initiate Process Improvement based on evidenced based data,
guidelines & study impact
• Combination of historical data and process improvement
![Page 23: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/23.jpg)
“When Has An Induction Failed”Simon & Grobman OB GYN vol 105; No. 4; April 2005 p.705
Length of
latent phase (h)
N (%) Cesarean
delivery
0-3 63 (16) 10 (16)
3.1-6 111 (28) 15 (14)
6.1-9 106 (27) 35 (33)
9.1-12 49 (12) 10 (29)
12.1-15 35 (8) 10 (29)
15.1-18 14 (4) 5 (36)
18.1-21 13 (3) 9 (69)
21.1-24 6 (2) 4 (67)
397 nullips > 36 weeks
Latent phase defined as
beginning of
oxytocin/amniotomy until 4
cm -80% effaced or 5 cm
Median time from oxytocin
to AROM 60 minutes
32% ripened
2% didn’t achieve active
phase
![Page 24: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/24.jpg)
Labor induction vs Expectant Management in Low Risk
Nulliparous Women Grobman NEJ Aug 9, 2018 p 513-523
Primary
outcome
Secondary
outcome
Induction
group
N=3059 (%)
Expectant
management
N=3037
Relative
risk
P
value
Composite
neonatal
132 (4.3) 164 (5.4) 0.80 (0.64-
1.00)
.049
Cesarean 569 (18.6) 674 (22.2) 0.84 (0.76-
0.93)
<0.001
Hypertension 277 (9.1) 427 (14.1) 0.64 (0.56-
0.74)
<0.001
Median duration
of stay in L&D-hr
20 (13-28) 14 (9-20) <0.001
![Page 25: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/25.jpg)
Obstetric Care Consensus
Safe Prevention of the Primary Cesarean Delivery
March 2014• Cervical ripening methods should be used when labor is induced in
women with an unfavorable cervix. IB
• If the maternal and fetal status allow, cesarean deliveries for failed
induction of labor in the latent phase can be avoided by allowing
longer durations of the latent phase (up to 24 hours or longer) and
requiring that oxytocin be administered for at least 12-18 hours
after membrane rupture before deeming the induction a failure. IB
![Page 26: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/26.jpg)
Obstetric Care Consensus
Safe Prevention of the Primary Cesarean Delivery
March 2014
• Before 41 0/7 weeks of gestation induction of labor generally should
be performed based and maternal and fetal medical indications.
Inductions at 41 0/7 of gestation and beyond should be performed to
reduce the risk of cesarean delivery and the risk of perinatal
morbidity and mortality. IA
![Page 27: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/27.jpg)
![Page 28: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/28.jpg)
Does Friedman’s data apply?
Of the 622 consecutive primigravida parturients at term,
500 analyzed
Ward patients 360 (72 %)
Private & semiprivate patients 140 (28%)
Stillbirth or neonatal death 4 (8/1000)
CPD 8 were absolute by
pelvimetry) 1.6%
Clinically Inert labor 46 (9.2%)
Pitocin 69 (13.8%)
22 times for elective induction & 47 times for stimulation
Friedman EA Dec 1955 Obstet Gynecol 6(6):567-89
![Page 29: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/29.jpg)
Does Friedman’s data apply to
contemporary obstetrics?
Of the 622 consecutive primigravida parturients at
term, 500 analyzed.
Spontaneous vaginal delivery 202 (40.4%)
Caudal anesthesia 42 (8.4%)
Low forceps vaginal delivery 256 (51.2%)
Mid forceps vaginal delivery 19(3.8%)
Cesarean delivery 9 (1.8%)
Breech vaginal delivery 14 (2.8%)
-All rectal and vaginal examinations were carefully noted
-One individual usually performed all exams during laborFriedman EA Dec 1955 Obstet Gynecol 6(6):567-89
![Page 30: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/30.jpg)
Obstetric Care Consensus
Safe Prevention of the Primary Cesarean Delivery
March 2014 ACOG
•Prolonged latent phase
• A prolonged latent phase (eg, greater than 20 hours in nulliparous women and
greater than 14 hours in multiparous women) should not be an indication for
cesarean delivery. IB
• Slow but progressive labor in the first stage of labor should not be an indication
for cesarean delivery. IB
![Page 31: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/31.jpg)
Fig. 3. The 95th percentiles of cumulative duration of labor from admission among singleton
term nulliparous women with spontaneous onset of labor, vaginal delivery, and normal
neonatal outcomes.Zhang. Contemporary Labor Patterns. Obstet Gynecol 2010.
![Page 32: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/32.jpg)
What is arrest of labor? Rouse DJ, Active-Phase Labor Arrest Oxytocin Augmentation for at least 4 hours OB GYN March 1999 vol. 93 No. 3 p 323-328
Time Eventual vagdelivery rate (%)
Chorioamnionitis (%)
Endometritis (%)
Transfusion (%)
After 2 hours oxytocin
Labor progress (159) 97 7 4 1
No labor progress (80) 74 14 7 1
No cervical exam (21) 86 0* 5 5
After 4 hours oxytocin
Labor progress (238) 94 6* 5 0
No labor progress (27) 56 22* 14 0
No cervical exam (22) 68 41* 0 0
* P< 0.001 study was prior to group B strep screening impact?
![Page 33: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/33.jpg)
Obstetric Care Consensus
Safe Prevention of the Primary Cesarean Delivery
March 2014
•Slow but progressive labor in the first stage of labor
should not be an indication for cesarean delivery. IB
•Cervical dilation of 6 cm should be considered the
threshold for the active phase of most women in
labor. Thus, before 6 cm of dilation is achieved,
standards of active phase progress should not be
applied. IB
![Page 34: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/34.jpg)
Obstetric Care Consensus
Safe Prevention of the Primary Cesarean Delivery
March 2014
•Cesarean delivery for active phase arrest in the first
stage of labor should be reserved for women at or
beyond 6 cm of dilation with ruptured membranes
who fail to progress despite 4 hours of adequate
uterine activity, or at least 6 hours of oxytocin
administration with inadequate uterine activity and
no cervical change. IB
![Page 35: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/35.jpg)
Active Labor PartogramAvailable in Toolkit
Re
sp
on
se
35
![Page 36: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/36.jpg)
![Page 37: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/37.jpg)
Zhang et al Contemporary Patterns of Spontaneous Labor with Normal Neonatal
Outcomes Dec 2010 OB GYN
![Page 38: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/38.jpg)
![Page 39: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/39.jpg)
Comparison of cost for components of medical care
![Page 40: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/40.jpg)
Harper OB GYN June 2012 Normal Labor in Induction
![Page 41: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/41.jpg)
![Page 42: Should we promote vaginal birth for women who are ... va… · Shoulder dystocia 1.0-2.0% 0% Respiratory morbidity](https://reader036.vdocument.in/reader036/viewer/2022081607/5ebe2cce467c95180153dc54/html5/thumbnails/42.jpg)
Time in hours for each centimeter of cervical dilation in
nulliparous women Harper OB GYN June 2012 p. 1113-
1118Cervical
dil cm
Ind labor P* Aug labor P* Spont labor
4-10 5.5 (1.8, 16.8) <.01 5.4 (1.8, 16.8) < .01 3.8 (1.2, 11.8)
3-4 1.4 (0.2, 8.1) <.01 1.2 (0.2, 6.8) <.01 0.4 (0.1, 2.3)
4-5 1.3 (0.2, 6.8) <.01 1.4 (0.3, 7.6) <.01 0.5 (0.1, 2.7)
5-6 0.6 (0.1, 4.3) 0.02 0.7 (0.1, 4.9) <.01 0.4 (0.06, 2.7)
6-7 0.4 (0.05, 2.8) 0.05 0.5 (0.06, 3.9) <.01 0.3 (0.03, 2.1)
7-8 0.2 (0.03, 1.5) .93 0.3 (0.05, 2.2) 0.01 0.3 (0.04, 1.7)
8-9 0.2 (0.03, 1.3) 0.80 0.3 (0.05, 2.0) <.01 0.2 (0.03, 1.3)
9-10 0.3 (0.04, 1.9) 0.13 0.3 (0.05, 2.4) <.01 0.3 (0.04, 1.8)