A Clinical Care Pathway for Obese Pregnant Women: A Pilot Cluster RCT
A Clinical Care Pathway for Obese Pregnant Women: A Pilot Cluster RCT
Clinics will be randomized to the use of the care pathway for obese pregnant women or
 standard care. Women who are (1) up to 20 weeks + 6 days gestation into their pregnancy, (2)
 are carrying one baby (not twins) that is healthy (no life threatening anomalies) and (3)
 have a Body Mass Index ≥ 30 kg/m², will be included. Data will be obtained from the Ministry
 of Health's Antenatal Records, charts, and for those in the intervention group, the care path
 (filled out by the practitioners - the participants' obstetrician, midwife, or family
 doctor). At the end of the study, practitioners will complete a survey, participate in
 structured interviews to understand barriers, facilitators, and motivators of using the care
 path.

 Primary Objective:

 To evaluate the feasibility of implementing and testing a clinical care pathway for obese
 pregnant women in a pilot cluster randomized controlled trial (RCT)

 Secondary Objectives:

 To obtain pilot data on A) process outcomes (steps of the pathway, e.g. what % of obese women
 receive a screen for diabetes) B) clinical outcomes (e.g. what % of obese women receive a
 diagnosis of diabetes), C) provider outcomes (e.g. Is the intervention acceptable, feasible &
 efficient? Barriers & facilitators to use, effectiveness? [Structured interviews])
STUDY DESIGN:

 Investigators propose a pilot cluster RCT with a 1:1 allocation ratio of clinics randomized
 to the clinical care pathway for obese pregnant women (intervention group) versus standard
 care (control group).

 Investigators have followed the SPIRIT statement (Standard Protocol Items: Recommendations
 for Interventional Trials)

 RANDOMIZATION:

 The unit of randomization will be the clinic providing pregnancy care. All pregnant women who
 meet inclusion criteria at a clinic randomized to the intervention will receive the
 intervention, while all pregnant women who meet the inclusion criteria at a clinic randomized
 to usual care will receive usual care. Investigators used a 1:1 allocation between the
 intervention and the control groups, with paired randomization by type of clinic
 (obstetrician-lead versus midwife-lead, since they likely differ regarding patient
 characteristics and health care, and pairing will aid in providing a reasonable balance of
 characteristics with a small sample size.) Investigators generated the randomization sequence
 using www.randomization.com. The randomization seed for obstetrical clinics was "21262" and
 the randomization seed for midwifery clinics was "23340".

 STUDY PROCESS:

 Clinics will be randomly allocated to the intervention or control group, in a paired fashion
 (so that one of the two midwifery clinics is randomized to the intervention group and the
 other to the control, given that both the clinical care and the women in the clinics are more
 likely to be similar between these two clinics).

 As the study involves a minimal/no-risk intervention, the Hamilton Integrated Research Ethics
 Board (HiREB) has approved clinics to be randomized and all eligible women at intervention
 clinics to receive the intervention (and all eligible women at control clinics to receive
 routine care); given that the intervention is standard of care, individual participant
 consent is not required. Informed, written consent of staff at the clinics which will be
 randomized to the intervention will be obtained prior to semi-structured interviews at the
 end of the study. Investigators do not plan an interim analysis given the minimal/no-risk
 nature of the intervention, and the pilot nature of the study, and hence investigators will
 not have a Data Safety Monitoring Board (DSMB), but will have a Steering Commitee.

 DATA COLLECTION:

 Data will be collected at the end of pregnancy from the:

 1. 2-page Antenatal Records mandated by the Ministry of Health: baseline characteristics*,
 clinical and process outcomes

 2. clinical care path (in intervention group): feasibility

 3. clinic and hospital charts: process and clinical outcomes

 4. care provider survey and structured interviews (in intervention group): provider
 outcomes.

 -  Baseline characteristics will include: maternal age, education level, pre-existing
 diabetes or hypertension or other co-morbidities, gestational age upon first visit
 to randomized clinic, pre-pregnancy body mass index, gravidity, and parity.

 SAMPLE SIZE:

 Investigators have provided a sample size justification, rather than a calculation for the
 following reasons:

 1. 'In general, sample size calculations may not be required for some pilot studies'

 2. Given that this is a feasibility study, it was not designed to have statistical power to
 detect a difference between the 2 treatment groups.

 3. The size of the intraclass correlation coefficient (ICC) required for a sample size
 calculation is currently unknown.

 The sample size was based on feasibility considerations as follows: Investigators
 conservatively estimate there would be a total of 142 participants available (71 per group)
 over 10 months of recruitment, at 8 clinics, with 80% of women in the intervention clinics
 receiving the intervention, (and 100% of women in the control group receiving usual care), a
 variable rate of obesity from 20-30% depending on the clinic, and a variable proportion of
 women presenting to the clinic for prenatal care at <20 weeks+6 days gestation ranging from
 15% in obstetrician-lead clinics to 85% in midwifery-lead clinics).

 This number of patients, 71 per group, exceeds one common number for a sample size for a
 pilot study, the "of at least 50 per group", since additional power is required for cluster
 designs.

 STATISTICAL ANALYSES:

 Baseline characteristics and co-morbid conditions will be compared between women receiving
 the intervention versus those in the control group. Since the design of the study involves
 paired randomization, hence paired analysis will be performed. Continuous data will be
 compared using a paired t test for means (standard deviations) or Wilcoxon test for paired
 medians (interquartile range), as appropriate. Paired proportions for categorical variables
 will be compared using a McNemar's test.

 The analysis of the primary outcome, feasibility, will be based on descriptive statistics of
 the proportions (%) of women in the intervention group who have the care path completed, and
 for whom care providers would recommend it. Analysis will be done at the patient level with
 the exception of care provider outcomes. Investigators will use intention to treat analysis,
 i.e. outcomes of all eligible women at the intervention clinic will be evaluated within the
 intervention group whether she received the intervention or not.

 The analysis of the secondary outcomes (process outcomes and clinical outcomes) will be done
 using McNemar's test to compare paired proportions of women in the intervention group who
 receive the recommended care to the proportion of women in the control group who do.

 Investigators will perform sensitivity analyses: 1) "per-protocol analysis", i.e.
 per-clinical care path and comparing the women in the intervention clinics for whom the
 clinical care path was actually used to all other women (both those who were at an
 intervention clinic but did not receive the clinical care path and those in the control
 group); 2) comparing results in women with and without complete data.

 Investigators will perform subgroup analysis to examine the outcomes at obstetrician clinics
 separately from those at midwifery clinics. Potential covariates which may not be evenly
 distributed between the intervention and control groups will be controlled for (e.g. age,
 socioeconomic status, etc). Since observations within each participating clinic will be
 assumed more likely to be similar than observations between clinics, a logistic model using a
 conditional (for paired data) generalized estimating equation (GEE) method will be performed
 to account for this clustering effect within clinics, incorporating both within-clinic and
 between-clinic variations. An intracluster correlation coefficient (ICC) and variance
 inflation factor (VIF) will also be calculated to assess the impact of the clustering effect.

 Results will be considered statistically significant at two-sided alpha=0.05 . A modified
 Bonferroni correction will be used given the multiple secondary outcomes. Analyses will be
 performed using SAS-PC statistical software (version 9.2; SAS institute Inc, Cary, NC).

 TEAM:

 Principal Investigator: Sarah McDonald, MD, MSc (Clinical Epidemiology), is an obstetrician
 and Associate Professor, McMaster University and Tier II Canada Research Chair in Maternal
 and Child Obesity Prevention and Intervention. Maternal weight and weight gain are the focus
 of her research program. She will oversee all aspects of this study.

 Co-Investigators:

 Lucy Giglia, MD, MSc (Epidemiology), a pediatrician, Associate Clinical Professor, McMaster
 University and a former Health Canada epidemiologist, is the Research Lead for the Division
 of General Pediatrics at McMaster Children's Hospital.

 Lehana Thabane, PhD, a statistician/RCT expert, is the Associate Chair of the Department of
 Clinical Epidemiology and Biostatistics and the Director of the Biostatistics Unit at the
 Centre for Evaluation Medicine, McMaster University and is experienced in the design,
 management and analysis of both RCTs and pilot RCTs.

 Collaborator:

 Cindy Maxwell, MD, was the co-author on the national guideline on the care of obese pregnant
 women, and the head of an obesity clinic for pregnant women at Mount Sinai Hospital in
 Toronto.

 Clinicians whose clinics would be potential recruitment sites have been and will continue to
 be involved in all phases of the study and development of the care pathway.
Inclusion Criteria:

 -  Inclusion criteria for clinics:

 1. location in southwestern Ontario (for proximity to the research team),

 2. availability of a clinician willing to serve as the local site lead, and

 3. lack of any type of existing clinical care pathway for obese pregnant women

 -  Inclusion criteria for participants:

 1. women with a pre-pregnancy (or in the event of inability to recall, then first
 measured) BMI >30 kg/m2

 2. with viable singleton pregnancies up to 20 weeks + 6 days gestational age upon
 first visit to randomized clinic

 Exclusion Criteria:

 -  Women with:

 1. a miscarriage or termination of pregnancy after enrollment,

 2. twins or higher order multiples or

 3. a fetus with a known lethal anomaly.