Aspiration technique-based device is more reliable in cervical stiffness assessment than digital palpation

Background

The purpose of this study was to compare the reliability and reproducibility of the traditional qualitative method of assessing uterine cervical stiffness with those of a quantitative method using a novel device based on the aspiration technique.

Methods

Five silicone models of the uterine cervix were created and used to simulate different cervical stiffnesses throughout gestation. The stiffness of the five cervix models was assessed both by digital palpation (firm, medium and soft) and with the Pregnolia System. Five self-trained participants conducted the device-based assessment, whereas 63 obstetricians and midwives, trained in digital palpation, conducted the cervical palpation.

Results

The results of the two methods were analyzed in terms of inter-and intra-observer variability. For digital palpation, there was no common agreement on the assessment of the stiffness, except for the softest cervix. When assessing the same cervix model for a second time, 76% of the obstetricians and midwives disagreed with their previous assessment. In contrast, the maximum standard deviation for the device-based stiffness assessment for intra- and inter-observer variability was 3% and 3.4%, respectively.

Conclusions

This study has shown that a device based on the aspiration technique provides obstetricians and midwives with a method for objectively and repeatably assess uterine cervical stiffness, which can eliminate the need to rely solely on a subjective interpretation, as is the case with digital palpation.

Nonadherence with ambulatory saliva sampling is associated with biased salivary testosterone estimates

OBJECTIVE

Nonadherence with scheduled saliva sampling, as encountered in ambulatory settings, can bias the estimation of salivary cortisol concentrations. This study is the first to estimate if such nonadherence is also associated with biased salivary testosterone concentration estimates.

METHODS

Using a standard ambulatory saliva-sampling protocol, we instructed pregnant women to collect saliva samples on two consecutive days at awakening, 1100h, 1500h, 2000h, and 2200h. We estimated testosterone concentrations in the saliva samples and participants' actual sampling times with an electronic medication event-monitoring system. We classified a saliva sample as adherent if it was sampled within a specific time window relative to its scheduled sampling time. We used a mixed-model analysis to distinguish between trait (number of adherent saliva samples per participant) and state (adherence status of a specific sample) adherence.

RESULTS

We included 60 pregnant women in this study. Seventy-five percent (448 of 600) of the scheduled samples indicated adherence with the sampling schedule. Participants' trait adherence was associated with their diurnal profiles of salivary testosterone estimates; that is, adherent participants had higher salivary testosterone estimates compared with nonadherent participants, F(1,58)=5.41, p=0.023, Cohen's d=0.67. The state adherence of a sample was associated with the salivary testosterone estimate of the related sample, F(1,469)=4.48, p=0.035, Cohen's d=0.20, with delayed sampling associated with lower salivary testosterone estimates.

CONCLUSIONS

The results suggest that common ambulatory nonadherence with scheduled saliva sampling is associated with biased salivary testosterone estimates. They will inform further studies estimating salivary testosterone with ambulatory saliva-sampling designs and highlight the relevance of strategies to improve or confirm adherence, beyond routinely used instructions.

Improving ambulatory saliva-sampling compliance in pregnant women: a randomized controlled study

Objective

Noncompliance with scheduled ambulatory saliva sampling is common and has been associated with biased cortisol estimates in nonpregnant subjects. This study is the first to investigate in pregnant women strategies to improve ambulatory saliva-sampling compliance, and the association between sampling noncompliance and saliva cortisol estimates.

Methods

We instructed 64 pregnant women to collect eight scheduled saliva samples on two consecutive days each. Objective compliance with scheduled sampling times was assessed with a Medication Event Monitoring System and self-reported compliance with a paper-and-pencil diary. In a randomized controlled study, we estimated whether a disclosure intervention (informing women about objective compliance monitoring) and a reminder intervention (use of acoustical reminders) improved compliance. A mixed model analysis was used to estimate associations between women's objective compliance and their diurnal cortisol profiles, and between deviation from scheduled sampling and the cortisol concentration measured in the related sample.

Results

Self-reported compliance with a saliva-sampling protocol was 91%, and objective compliance was 70%. The disclosure intervention was associated with improved objective compliance (informed: 81%, noninformed: 60%), F(1,60)  = 17.64, p<0.001, but not the reminder intervention (reminders: 68%, without reminders: 72%), F(1,60)  = 0.78, p = 0.379. Furthermore, a woman's increased objective compliance was associated with a higher diurnal cortisol profile, F(2,64) = 8.22, p<0.001. Altered cortisol levels were observed in less objective compliant samples, F(1,705) = 7.38, p = 0.007, with delayed sampling associated with lower cortisol levels.

Conclusions

The results suggest that in pregnant women, objective noncompliance with scheduled ambulatory saliva sampling is common and is associated with biased cortisol estimates. To improve sampling compliance, results suggest informing women about objective compliance monitoring but discourage use of acoustical reminders.