Spirometry is a non-invasive technique that measures the vital capacity,
forced expired volume in one second, and rates airflow at various lung
volumes. Measurement of the forced vital capacity and corresponding flow rates
is the most commonly used test to detect the presence of lung disease and to
monitor changes in severity and response to treatment.  
  
Patient-initiated spirometric recording per 30-day period of time includes
reinforced education, transmission of spirometric tracing, data capture,
analysis of transmitted data, periodic recalibration and physician review and
interpretation.  
  
The use of peak flow meters by patients, and their recording and reporting of
the results to their physician, has been a standard means of monitoring
patients with pulmonary dysfunction at home.

Transtelephonic spirometry has also been investigated in lung heart-lung
transplant recipients who underwent monitoring of lung rejection with home
spirometry. Scientific conclusions support the utility of home monitoring in
this clinical setting. Home spirometry and telespirometry is considered
reasonable and medically necessary for lung transplant recipients when the
following is met:

  
1.Lung transplant patient

  
2\. Adherence to home spirometry measurements of 80%. This is defined by
transmission of data at least 80% of the time.

  
3\. If patient is non-compliant* then they are not eligible for further home
spirometry services.

  
*Non-compliance is defined as no measurements or transmitted for 7 consecutive days x 2. If they are non-compliant for one week the coordinator can reach out and offer education. If non-compliance continues (no measurement for 7 days) then the service will no longer be eligible for coverage.   
Home spirometry and telespirometry is considered experimental and
investigational for all other indications (asthma, idiopathic pulmonary
fibrosis, and persons with other chronic pulmonary diseases/disorders (e.g.,
emphysema)) because there is a lack of evidence that it will improve the care
of persons with these disorders.



A consensus report from the Pulmonary Council of the International Society for
Heart and Lung Transplantation (ISHLT) set out to standardize the nomenclature
of chronic lung allograft dysfunction (CLAD) and its clinical phenotypes to
facilitate collaboration among centers investigating the pathogenesis,
prevention, and treatment of CLAD.1 CLAD is defined as a substantial and
persistent decline (20%) from baseline in measured FEV1. The baseline value
is computed as the mean of the best 2 post-operative FEV1 measurements (taken
>3 weeks apart). CLAD can present either as a predominantly obstructive
ventilatory pattern, a restrictive pattern, or a mixed obstructive and
restrictive pattern that is not explained by other conditions. Consistent
pulmonary function testing (PFT) is the leading strategy for early detection
of CLAD. While home spirometry devices may provide more variable results,
evidence supports it as a useful modality to detect early changes in graft
function and may assist providers in decision making.

A systematic review was conducted to determine the effectiveness of home
spirometry as a bronchiolitis obliterans syndrome (BOS) detection tool in lung
transplant recipients. Eight randomized control trials were included. Authors
conclude that home spirometry may be a reliable and safe alternative for lung
transplant recipients although they acknowledge the study did not address the
impact of early detection on survival outcomes.2

Finkelstein et al. performed a randomized control trial to determine the
relative performance of a computer-based Bayesian triage algorithm compared
with a manual nurse-based triage system in terms of patient health and health-
related quality of life (QOL) in lung transplant recipients. The trial had 65
lung transplant recipients assigned to either the Bayesian algorithm or nurse
triage study arm. Subjects monitored and transmitted spirometry and
respiratory symptoms daily to the data center using an electronic
spirometer/diary device. Subjects completed the Short Form-36 (SF36) survey at
baseline and after 1 year. End points were change from baseline after 1 year
in forced expiratory volume at 1 second (FEV1) and quality of life (SF-36
scales) within and between each study arm. A total of 65 subjects (control
arm=35, intervention arm=30) yielded an overall adherence of 83% for data
collection and 88% adherence during the first year. No significant differences
in physical (FEV1) or quality of life (SF-36) measures from baseline after HM
triage follow-up for subjects in the two arms, suggesting that subjects'
physiological and functional outcomes were similar regardless of the triage
method used to monitor HM data. 3

Fadaizadeh et al. conducted pilot study to evaluate the role of home
spirometry in follow up of lung transplant recipients and early detection of
complications over a 6-month period. Four subjects were included with 2 of
those being matched control subjects. Adherence was 80% and 61% in the active
participants. The authors conclude that HS is a viable method for monitoring.4
The team conducted further investigation with a prospective cohort study on 15
lung transplant recipients to assess patient adherence and satisfaction with
telespirometry following lung transplant over 6 months. Study participants
were instructed to send home spirometry results and their clinical symptoms
via SMS message. Patients' level of satisfaction showed a sense of increased
support from medical staff was rated highest (92.9%) while satisfaction with
the spirometer was rated lowest (35.7%). Average patient compliance at
baseline was 80% compared to 27% at study completion, resulting in an average
of 78% throughout the study duration. Authors conclude telespirometry is an
efficient method of monitoring lung transplant recipients with increased
patient satisfaction and adherence.5

A single center retrospective cohort study included 427 adult patients that
received the first lung transplantation (LTx) in a specialized outpatient
clinic between 1-1-2010 and 12-31-2013. The primary outcome was allograft
survival. The secondary outcomes were patient survival, prevalence of CLAD,
hospitalizations within the first year after transplantation, renal function
after 5 years, and quality of life within the first 3 years after
transplantation. The median adherence was 86% on 6,623 visits and was used as
the cut off and as a discriminator between good and suboptimal adherers.
Patients with good adherence within the first 3 years yielded more favorable
5-year allograft results (74% vs. 60%, p = 0.003) and patient survival (79%
vs. 64%, p<0.001) and lower prevalence of chronic allograft dysfunction (33%
vs. 45%, p = 0.011) after 5 years when compared to patients with suboptimal
adherence.6

A single center retrospective study of adult lung transplant recipients on
long term azithromycin for bronchiolitis obliterans (BOS) was performed to
evaluate if macrolide-refractory progression could be identified earlier with
home spirometry (HS) compared to office spirometry (OS). A total of 239 lung
transplant patients were included. Change in FEV1 +/- 10% from FEV1 at
azithromycin initiation for _>_ 7 consecutive days in HS or _>_ 2 measures in
OS were taken as cut-off for response or progression. 67% (161/239)
demonstrated progression and an additional 8% (n=19) showed initial response
followed by relapse. Time to progression was 29 (13-96) days earlier with HS
than in OS. Response or stabilization conferred significant improvement in
survival (p=0.005). Authors concluded HS identified azithromycin refractory
patients significantly earlier than OS, possibly facilitating aggressive
treatment escalation that may improve long-term outcome.7

An observational feasibility study was performed to explore the feasibility of
rural home telemonitoring for patients with lung cancer. Five patients
received usual care after discharge; and five had telemonitors set up at home
for 14 days with daily phone calls for nurse coaching; mid- and end-study data
were collected by phone and in homes through two months. One of 5 usual care
and 3 of 5 monitored patients completed the study. Authors concluded
telemonitored data transmission was feasible in rural areas with high
satisfaction and symptom data and physiologic data were inconsistent based on
disease. 8 Limitations included small sample size and short-term follow-up.

Wang and associates explored new computer-based approaches for the early
detection of bronchopulmonary events in a population of lung transplant
recipients following a home monitoring protocol. Twenty-eight transplant
recipients had a minimum home monitoring period of 60 days. Spirometry and
clinical data were collected daily at home by lung transplant recipients and
transmitted weekly to the study data center. The majority of event were
captured using forced expiratory volume in 1 second or symptoms (sensitivity,
80-90%) at an acceptable level of false alarms. Mean detections occurred
6.6-10.8 days earlier than the known event records. Based on these findings,
the authors concluded the approach was useful for early discovery of pulmonary
events.9

According to UpToDate, many centers utilize routine home spirometry but note
the limitation of patient compliance with this modality is inconsistent.10

The current literature on the use of transtelephonic spirometry suggests
limitations of patient compliance and potential issues with spirometry
equipment calibration. Despite these obstacles, patients show benefits from
the early detection of pulmonary complications and provider awareness. Based
on the emergence of supporting literature and societal guidance coverage for
transtelephonic spirometry for lung transplant patients is considered
reasonable and medically necessary.