Sleep & CPAP Report — 2026-09-24

🚩 Flags

• AHI 1.65 — vs 30d avg 2.18 (-24.3%). 7d avg 2.25 (-26.8%). OA collapse: 3 vs 30d avg 10.23 (-70.7%) — cleanest apnea night in 7. H 6, CA 1, RERA 0. Best AHI since 2026-09-18 (0.87).
• Awake 1.00 min — extreme outlier low. Only 2 of 71 matched nights have awake<2 min; tonight is the 3rd-lowest in history. Sleep efficiency 99.72%. Vs 30d avg 8.68 min (-88.4%), vs 7d 10.68 (-90.6%).
• ⚠️ Deep sleep 9.69% — bottom 10th percentile. Vs 30d avg 14.29% (-32.2%) and 7d 13.85% (-30.0%). Deep min only 34.6 (vs 30d ~53). Notable given the near-zero awake time — the improvement in continuity did NOT convert into deeper sleep.
• ⚠️ Week-over-week deep-sleep decline is now a sustained pattern. Recent 7d 2026-09-18–24 = 12.57% deep vs prior 7d 2026-09-11–17 = 17.65% (Δ -5.08 pp, -28.8%). 4 of the last 7 nights are below 13% deep. Trend is real, not a single-night blip.
• Leak_Max spike 28.8 L/min but Leak_Avg 0.59 and Leak_90 1.20 are both low — signature of a brief mask displacement, not sustained leak. Nothing like the 2026-09-23 spike (L90 12.0, LAvg 2.87).
• Time in bed 358.3 min (5h 58.3m); total sleep 357.3 min. CPAP usage 6.05h — slightly below both 7d (6.29) and 30d (6.47) averages, at the lower end of the recent range.

Summary Table — Night of 2026-09-24

Metric	Value
Sleep start	2026-09-24T23:18:14-05:00
Time in bed	358.3 min (5h 58.3m)
Total sleep	357.3 min (5h 57.3m)
Sleep efficiency	99.72%
Awake time	1.00 min
Core (N1+N2) sleep	235.84 min / 66.01%
Deep (N3) sleep	34.62 min / 9.69%
REM	86.81 min / 24.30%
CPAP usage hours	6.05
Session count	1
AHI	1.65
RDI	1.65
Obstructive apneas (OA)	3
Hypopneas (H)	6
Central apneas (CA)	1
Unclassified apneas (UA)	0
RERA	0
Pressure_Avg	7.36
Pressure_Min	4.00
Pressure_Max	11.76
Pressure_90th	10.18
Leak_Avg	0.59
Leak_Max	28.80
Leak_90th	1.20
FL_Avg	0.0167
FL_P95	0.09
FL_Max	0.45
Min_Above_005	39.1
Min_Above_010	15.2
Min_Above_020	3.4
Frac_NonZero (FL samples)	29.15%

Comparison to Trailing Averages

Metric	Tonight	7d avg	30d avg	Δ vs 7d	Δ vs 30d
AHI	1.65	2.25	2.18	-26.8%	-24.3%
OA count	3.00	9.14	10.23	-67.2%	-70.7%
H count	6.00	4.43	2.83	+35.5%	+111.8%
CA count	1.00	0.43	1.00	+133.3%	+0.0%
RERA count	0.00	0.57	0.73	-100.0%	-100.0%
Pressure_Avg	7.36	7.59	7.44	-3.0%	-1.0%
Pressure_90	10.18	9.97	9.92	+2.1%	+2.6%
Leak_Avg	0.59	1.11	0.82	-46.8%	-28.3%
Leak_Max	28.80	19.71	17.88	+46.1%	+61.1%
Leak_90th	1.20	3.43	2.44	-65.0%	-50.8%
Usage hours	6.05	6.29	6.47	-3.7%	-6.5%
FL_P95	0.09	0.10	0.09	-7.4%	-3.2%
Min_Above_010	15.20	17.46	16.50	-12.9%	-7.9%
Min_Above_020	3.40	3.51	3.68	-3.3%	-7.6%
Awake min	1.00	10.68	8.68	-90.6%	-88.4%
TIB min	358.27	373.90	370.67	-4.2%	-3.3%
Total sleep min	357.27	363.22	361.99	-1.6%	-1.3%
Deep %	9.69	13.85	14.29	-30.0%	-32.2%
REM %	24.30	24.76	25.08	-1.9%	-3.1%
Core %	66.01	61.39	60.63	+7.5%	+8.9%

Week-over-Week Deltas (recent 7d 2026-09-18–2026-09-24 vs prior 7d 2026-09-11–2026-09-17)

Metric	Recent 7d	Prior 7d	Δ	Δ %
AHI	2.144	2.383	-0.239	-10.0%
OA	8.000	12.000	-4.000	-33.3%
CA	0.286	1.429	-1.143	-80.0%
Pressure_Avg	7.619	7.297	+0.321	+4.4%
Leak_Avg	1.119	0.536	+0.583	+108.8%
Leak_90	3.429	1.371	+2.057	+150.0%
Deep % (Apple)	12.568	17.651	-5.083	-28.8%
REM % (Apple)	25.318	27.021	-1.704	-6.3%
Awake min (Apple)	7.957	8.817	-0.860	-9.8%
Sleep min (Apple)	365.801	319.638	+46.163	+14.4%
FL_P95	0.100	0.087	+0.013	+14.8%
Min_Above_010	17.914	14.743	+3.171	+21.5%
Min_Above_020	3.529	4.429	-0.900	-20.3%

Recent 10-Night Context

Date	AHI	OA	CA	PAvg	P90	LAvg	LMax	L90	FL_P95	MinAbv010	MinAbv020	Deep%	REM%	Awake
2026-09-15	1.93	10	0	7.76	10.02	0.74	14.40	2.40	0.12	21.2	6.9	12.66	24.62	8.53
2026-09-16	2.85	16	4	7.20	9.68	0.09	8.40	0.00	0.08	13.5	2.8	9.37	22.95	10.04
2026-09-17	2.41	11	2	7.17	9.22	0.52	10.80	1.20	0.07	12.0	3.3	18.64	20.41	20.07
2026-09-18	0.87	5	0	7.07	9.56	0.18	8.40	0.00	0.09	16.4	2.9	11.51	23.16	10.54
2026-09-19	3.23	15	0	7.60	9.64	0.41	14.40	1.20	0.10	16.8	2.1	10.83	25.42	14.55
2026-09-20	2.18	7	0	8.21	10.54	1.85	27.60	6.00	0.13	28.6	7.0	8.70	31.40	14.55
2026-09-21	1.94	5	1	7.82	10.46	0.90	14.40	1.20	0.09	16.2	2.9	13.07	23.78	5.52
2026-09-22	3.20	12	0	7.49	10.32	1.03	36.00	2.40	0.10	14.8	3.1	15.33	23.07	4.01
2026-09-23	1.94	9	0	7.78	10.06	2.87	26.40	12.00	0.10	17.4	3.3	18.83	26.11	5.52
2026-09-24	1.65	3	1	7.36	10.18	0.59	28.80	1.20	0.09	15.2	3.4	9.69	24.30	1.00

CPAP → Sleep-Stage Correlations (all 71 matched nights)

Correlations computed across full available history (2026-07-13 → 2026-09-24) where both a CPAP daily row and a per-night Apple Watch sleep-stage session exist.

Pair	the user r	Interpretation
AHI vs deep_pct	-0.038	negligible
AHI vs awake_min	-0.193	weak negative
OA vs awake_min	-0.081	negligible
CA vs deep_pct	-0.065	negligible
Leak_Avg vs deep_pct	-0.086	negligible
Leak_90th vs deep_pct	-0.103	weak negative
Leak_Max vs awake_min	-0.126	weak negative
FL_P95 vs awake_min	-0.094	negligible
Min_Above_010 vs deep_pct	-0.058	negligible

Bucket comparison (Leak_90 median split, median = 1.2): - Low-leak nights (n=38): mean deep% 15.21, awake 13.65 min - High-leak nights (n=33): mean deep% 13.73, awake 12.09 min - Δ (high – low): deep% -1.48 pp, awake -1.57 min

The directional pattern (higher leak → lower deep %) remains weakly negative, consistent with prior weeks. Tonight fits the pattern loosely: L90 was low (1.20, low-leak bucket) yet deep% was also low — reinforcing that leak is not the primary driver of tonight's deep-sleep shortfall.

Interpretation

Tonight is a study in mixed signals. Respiratory event control was excellent: only 3 obstructive apneas — a 7d/30d improvement of 65–70% — and the third-lowest awake time in the entire tracked history (1.00 min, sleep efficiency 99.7%). By those measures this was the user's cleanest night in over a week.

Yet deep sleep collapsed to 9.69% (bottom decile), driving core sleep up to 66% — the highest core-share in the recent 10-night window. This is the more important story: with awake time essentially eliminated, deep sleep did not backfill. Instead the architecture stayed in N1/N2. Possible contributors, in rough order of plausibility:

1. Short total sleep (5h 57m) — deep sleep concentrates in the first third of the night, and a curtailed night still yields ~normal absolute deep minutes but a lower share. Tonight's 34.6 deep-min is ~65% of the 30d absolute mean (~53 min), so this is a real reduction, not just a percentage artifact.
2. Emerging week-over-week trend — deep% has now run 12.57% for 7 nights against a prior week of 17.65%. If sleep timing, alcohol, exercise timing, or evening screen exposure has shifted in the past ~week, that is worth checking.
3. CPAP factors — leak, flow limitation, and event counts are all within recent norms tonight and are unlikely to explain the deep-sleep drop on this night in isolation.

None of tonight's numbers cross clinical thresholds (AHI < 5 by a wide margin, leak well within mask spec, usage 6+ hours). The pattern to keep watching is the week-over-week deep-sleep step-down.

Caveats

• Sleep session started at 2026-09-24T23:18:14-05:00 — matched to the 2026-09-24 CPAP file. Nights where the Apple Watch session begins after midnight are attributed to the previous CPAP calendar date.
• Apple Watch SpO2/pulse channels not present in current CPAP CSV export.
• Correlations are directional/small-effect only — single-night deviations often exceed what correlations alone would predict.
• All flagged metrics remain within clinically safe ranges (AHI < 5, leak within mask spec); flags mark deviations from the user's own recent baseline, not clinical thresholds.
• Matched-night count this report = 71 (vs 85 in the 2026-09-23 report); this run counts only nights where both a per-day CPAP row and a per-day Apple Watch sleep-stage session are present in the current files, which drops some of the multi-day roll-up early nights and any nights whose duplicate JSONs weren't resolved to the primary copy. Correlations are qualitatively unchanged.
• The 1.00-min "awake time" reading is credible given Apple Watch's minute-level resolution but should be treated as effectively "zero interruptions detected", not as certainty of unbroken sleep.